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y," LIBRARY
Michigan State

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This is to certify that the

thesis entitled
MOLECULAR DYNAMICS OF A LIQUID CRYSTAL THROUGH BAND SHAPE
ANALYSIS; A STUDY OF 4-CYANO-4'-PENTYLBIPHENYL (SCB)
WITH A COMPUTERIZED RAMAN SPECTROMETER

presented by

Stephen Michael Gregory

has been accepted towards fulfillment
of the requirements for

 

 

Ph. D . degree in ChemistrL

git/5g, .2
I

Major professor

Date August 24, 1979

 

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MOLECULAR DYNAMICS OF A LIQUID CRYSTAL THROUGH BAND SHAPE
ANALYSIS; A STUDY OF 4-CYANO-4'-PENTYLBIPHENYL (SCB)
WITH A COMPUTERIZED RAMAN SPECTROMETER

BY

Stephen Michael Gregory

A DISSERTATION

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Chemistry

1979

ABSTRACT

MOLECULAR DYNAMICS OF A LIQUID CRYSTAL THROUGH
BAND SHAPE ANALYSIS; A STUDY OF 4-CYANO-4'-
PENTYLBIPHENYL (SCB) WITH A COMPUTERIZED RAMAN SPECTROMETER

3)»

Stephen Michael Gregory

This work was undertaken to understand more about the nature of
liquids and the forces that hold liquid molecules together. The type
of liquid system that was chosen for this study was a nematic liquid
crystal system. The system was probed by Raman spectroscopy and
viscosity measurements. The nematic liquid crystal system that was the
most fruitful was 4-cyano-4'-pentylbiphenyl (SCB).

The Raman spectrometer used in this work was computerized for the
project and software was written for both a minicomputer and a large
computer to analyze the data. SCB was synthesized from 4-bromobiphenyl
for the experiments.

The Raman lineshape analysis of SCB was not very conclusive due to
experimental difficulties. The viscosity measurements were converted
to reorientational relaxation times by use of several modified Stokes-
Einstein equations. These results covered a range of one magnitude
around 1 x 10-10 seconds. The analysis indicated that sticking boundary
conditions with a microviscosity correction came the closest to the
Raman lineshape results, but there was a one order of magnitude

difference, with the Raman results being the shortest.

To Joyce

ii

II.

III.

IV.

VI.

VII.

VIII.

TABLE OF CONTENTS

LIST OF TABLES . . .
LIST OF FIGURES . . . .
INTRODUCTION . . . . . .
LIQUID CRYSTAL SYSTEMS .
THEORETICAL
EXPERIMENTAL .
INSTRUMENTAL .

LINESHAPE ANALYSIS OF SIMPLE LIQUIDS .

LIFETIME STUDY OF LIQUID CRYSTAL SYSTEMS .

CONCLUSIONS

APPENDIX A. PROGRAM DATCOL
APPENDIX B. PROGRAM MOVE
APPENDIX C. PROGRAM CRUNCH
APPENDIX D. PROGRAM LNSHP .
APPENDIX E. TEST ROUTINE

LIST OF REFERENCES .

iii

iv

22

34

54

62

95

98

, 109
, 113
. 138
. 148

. 150

TABLE 1.

TABLE 2.

TABLE 3.

LIST OF TABLES

DENSITY 0F 4-CYANO-4'«PENTYLBIPHENYL . . . . . . . . . . 89

EXPERIMENTAL AND CALCULATED vrscosrrrss or
4-CYANO-4'-PENTYLBIPHENYL . . . . . . . . . . . . . . . . 89

VISCOSITIES, EFFECTIVE MOLECULAR VOLUMES, AND
RELAXATION TIMES FOR 4-CYANO-4'-PENTYLBIPHENYL . . . . . 91

iv

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

FIGURE

10.

11.

12.

13.

14.

15.

16.

17.

LIST OF FIGURES

A BLOCK DIAGRAM OF THE LASER RAMAN SYSTEM USED
FOR THIS WORK . . . . . . . . . . . . . . . .

THE GLASS RAMAN CELL USED FOR SIMPLE LIQUIDS

THE COPPER CUVETTE HOLDER USED FOR RAMAN EXPERIMENTS
RUN AT TEMPERATURES AROUND 25°C . . . .

THE COPPER CUVETTE HOLDER USED FOR RAMAN EXPERIMENTS
RUN AT TEMPERATURES AROUND 100°C

THE OVERALL SCHEMATIC OF THE INTERFACE BETWEEN A
PDP 8/I MINICOMPUTER AND A JARRELL-ASH RAMAN
SPECTROMETER . . . . . . . . . . .

A FLOWCHART OF PROGRAM DATCOL.SV.
A FLOWCHART OF PROGRAM MOVE.SV.

A FLOWCHART OF PROGRAM CRUNCH.SV.
A FLOWCHART OF PROGRAM LNSHP.

SURVEY SCAN OF THE RAMAN SPECTRUM OF ACETONITRILE .
THE 2250 cm.1 VIBRATIONAL BAND OF ACETONITRILE,
USED AS INPUT TO PROGRAM LNSHP. . . . .

THE OUTPUT OF PROGRAM LNSHP FOR THE 2250 cm-1
VIBRATIONAL BAND OF ACETONITRILE

STRUCTURES OF EBB, SCB, AND MBBA
ISOTROPIC PHASE

SURVEY RAMAN SPECTRA OF MBBA. TOP:
(45°C); BOTTOM: NEMATIC PHASE (25°C)

SURVEY RAMAN SPECTRA OF SCB. BOTTOM: SOLID PHASE
(15°C); CENTER: NEMATIC PHASE (25°C); TOP:
ISOTROPIC LIQUID PHASE (45°C) . . .

2225 cm"1 SCATTERING FOR SCB IN THE NEMATIC

PHASE (25°C) . . . . . . . .

2225 cm'1 SCATTERING FOR SCB IN THE ISOTROPIC
PHASE (45°C) . . . . . . . . . . . . . . .

24

26

29

31

36

39

44

47

51

56

58

60

65

67

71

73

75

FIGURE 18.

FIGURE 19.

FIGURE 20.

FIGURE 21.

FIGURE 22.

INSTRUMENT FUNCTION FOR THE JARRELL-ASH

SPECTROMETER; Ar LASER PLASMA LINE AT 4880 A . . . .

l

LINESHAPE FIT FOR THE 2225 cm“ RAMAN BAND OF SCB

IN THE ISOTROPIC PHASE (45°C)

LINESHAPE FIT FOR THE 2225 cm"1

IN THE NEMATIC PHASE (25°C)

I 0. Q

RAMAN BAND OF SCB

VIBRATIONAL LINESHAPE FIT TO THE 2225 cm.1 RAMAN BAND

OF SCB IN THE ISOTROPIC PHASE (45°C)

VIBRATIONAL LINESHAPE FIT TO THE 2225 cm“
OF SCB IN THE NEMATIC PHASE (25°C)

vi

1

RAMAN BAND

78

80

82

85

87

I. INTRODUCTION

In order to understand the nature of liquids and the forces that
hold liquid molecules together one must find a suitable probe into the
interactions within the liquid state. This work deals with the selec-
tion of such a probe and the determination of its efficacy in answering
some of the questions raised by theory and other experiments.

The probe chosen for this work was Raman spectroscopy. The line-
shape contribution to a vibrational Raman band from molecular rotations
can be separated out and measured.1 The functional form used to repro-
duce the rotational (or reorientational) contribution to the overall
bondshape can possibly shed some light on the liquid state being
studied. One such mathematical model is a Lorentzian function, which
corresponds to random rotational behavior and has a half-width that
is related to the rotational correlation time (the l/e decay time). If
rotation in the liquid under study is not random then some other func-
tional form will better fit the experimental data.

One question this work has attempted to address is what happens
to the rotational motion, and also to the rotational bandshape, when a
liquid passes from an isotropic State to an anisotropic state? Nematic
liquid crystals were chosen as prototypic systems. The theoretical
development for such a system suggests that the true rotational reorien-
tation function will be a sum of Lorentzians, which would not necessarily
be matchable with a single Lorentzian.2 The liquid crystal that proved
to be the most fruitful, and was therefore studied in most detail, was

4-cyano-4'-pentylbiphenyl (SCB). Its reorientational time, as

determined from the shape of the C E N stretching mode, was found to be
very slow; in fact, it was so slow that a distinction between single or
multiple Lorentzian lineshapes could not be drawn within the experimental
error. However, there do appear to be significant differences between

the bandshapes in the isotropic and nematic phases. The data obtained
were good enough to show that this system behaves like others of similar
size3 and that its overall correlation function is dominated by vibrational
relaxation on a short time scale (<5 psec).

The same experiment from which data for the rotational lineshape
calculations is collected also provides sufficient data for calculation
of the vibrational lineshape. From the vibrational lineshape for each
liquid phase the vibrational correlation times were calculated and found
to be consistant with studies of other liquid crystals. In order to
obtain information about flow characteristics, the temperature dependence
of the apparent flow viscosity of SCB was determined and reorientational
times were calculated using the Stokes-Einstein equation with a variety
of boundary conditions.

Because Raman intensity data are difficult to measure precisely,
and because good data are required at closely spaced intervals well
into the wings of a Raman band, traditional strip-chart recording of a
Raman spectrum was not feasible for these studies. Therefore, as part
of this dissertation research, an interface between a minicomputer and
a Raman instrument was designed and constructed. This interface will
be described, as will the software and the Operating parameters which
must be defined for efficient utilization of the computerized Raman

spectrophotometer.

II. LIQUID CRYSTAL SYSTEMS

Liquid crystals have been studied since the middle of the 19th
century. Most of the early work was devoted to describing the liquid
systems; it was not until the 1920's that a quantitative theory for
liquid crystals was presented. It was also during that period that the
first works on the viscosity behavior of liquid crystals were presented.4

Liquid crystals can be divided into two categories: thermotropic
and lyotropic. Lyotropic liquid crystals are prepared by mixing two
or more components, one of which generally has polar molecules. These
systems can exhibit many structures, with one of the most common systems
being a lipid-water system. Thermotropic liquid crystals are prepared
by heating certain organic or organometallic compounds. The two classes
of thermotropic liquid crystals are called smectic (from the Greek word
meaning grease or slime) and nematic (from the Greek word meaning
thread).s

In a smectic liquid crystal the molecules are arranged in layers
with their long axes parallel to each other. The molecules can move in
two directions in the plane, and they can rotate about one axis. Within
the layers they can be arranged either in neat rows or randomly distri-
buted. The layers can slide, without much hindrance, over neighboring
layers.

In a nematic liquid crystal the only structural restriction is that
the molecules maintain a parallel or nearly parallel arrangement to one
another. The molecules are mobile in three directions and can rotate

freely about one axis. This molecular arrangement can be compared to

a long box of pencils where the pencils can roll and slide back and
forth, but they remain parallel to one another in the direction of their
long axes.

Liquid crystals also exhibit an isotropic liquid State. There is
a well defined transition point as these compounds pass from a liquid
crystalline state to an isotropic liquid state. The temeprature at
this point is denoted TC and it is called the clearing point, since
all cloudiness in the liquid vanishes. There can also be transitions
between different liquid crystalline states,such as from a smectic
state to a nematic state.

Molecular structure plays an important role in the liquid crystal—
line states that a molecule exhibits. Small alterations in the structure
will sometimes greatly affect the properties of the liquid crystal
compound.6 Changes that increase lateral separation and decrease
lateral attractions tend to decrease the thermal stabilities of liquid
crystalline states. If the change increases the polarity and/or
polarizability of the molecule, then the thermal stability will be
increased.

Modification of the alkyl tail length on liquid crystalline
molecules has two opposing effects. The longer molecules are less
readily rotated out of the ordered states and their overall polariza-
bility is increased. These two factors will increase the thermal
stability of the system. On the other hand, the aromatic centers are
further apart, and this tends to result in a decrease in thermal

stability.

Many theories have been proposed that try to describe the various
liquid crystalline states; some of them will be briefly discussed here.7"14
Ericksen7 suggests a continuum theory that describes the macroscopic
behavior of nematic liquid crystals, and has used this theory to
investigate the propagation of orientation waves and viscosity. In
this model, the nematic fluids are considered to be incompressible and
thermal effects are ignored. It was found that associated with any
discontinuity in orientation there is a discontinuity in motion, which
promotes dissipation of the orientation wave. The continuum theory
predicts that the fluid will behave as a Newtonian fluid at high shear
rates. If the shear rate is low, then there will be some small differences
in the normal stress. These stress effects should be similar to those
found in polymer solutions.

Franklin8 has modified Kirkwood's diffusion theory to take into
account anisotropic viscosity, molecular order, and the detailed
geometry of the molecules. This theory adopts the assumption that the
molecules are rigid rods, and predicts a Stokes-Einstein like behavior
for the relationship between the rotational diffusion of a liquid
crystal and its viscosity. It also predicts a temperature dependence
of the broadening of Rayleigh peaks.

Wadati and Isihara9 present a theory based on cluster expansions
for a non-uniform system. They obtained good success in predicting
phase transitions of rod—like molecules in two dimensions. They predict
that the mechanism for the nematic-smectic phase transition is the same

as that for hard-sphere particles.

Freedlo has looked at a stochastic-molecular theory for spin
relaxation of liquid crystals. He has shown that the statistical

independence between the overall molecular reorientational motion and
the order fluctuations can be removed.

Cotter11-14 has developed a theory in which the short range inter-
molecular repulsions are represented by repulsions between hard sphero— '
cylinders and the intermolecular attractions are treated self-consistently
in the mean field approximation. This attraction tends to align the
molecular axes in space and provides a uniform background potential.

This model suggests that short range anisotropic intermolecular repulsions
play a major role in stabilizing nematic mesophases.

Raman spectroscopy has been used to delve into the molecular
structure and forces that Characterize liquid crystal systems. Schnur15
noticed new Raman bands that changed as the liquid crystal phase changes
for alkoxyazobenzens. These low frequency bands were attributed to
an accordian mode of the alkyl tail of the molecules under study. The
temperature dependence of these bands indicate that a greater number of
conformations of the tail are allowed as the order of the fluid decreases.

Priestley and Pershunl6 and Jen et al.17 have developed a formalism
by which the order parameter of a nematic liquid crystal can be obtained
using depolarization ratios of Raman bands. The technique used has
shown promise for being able to study the internal structure of various
smectic phases, since the limitations are how well the incident beam

can be focused and how selectively the scattered light can be collected.

A good discussion of the vibrational spectroscopy of liquid crystals
has been presented by Bullkin.18 He has noticed pretransitional effects
in both the infrared and Raman spectra of nematic liquid crystals.

The indication is a "softening" of a mode that arises from a hindered
rotation or translation of the system. Calculations made on these modes
have shown that there exists strong coupling among the modes along
certain axes, while much weaker coupling exists along others.

Gray and Mosley19 have looked at the Raman spectra of 5C3 and

SCB-d They assigned the observed Raman bands to various vibrational

ll'
modes of the molecules. They also explained some of the frequency shifts
and intensity changes observed upon transition from one phase to another.
Most of these changes were due to a freeing of translational and

rotational modes.

Many investigators have studied the viscosity of liquid crystals.20-34
Fisher and FredricksonzO investigated the effect of interfacial orienta-
tion on the viscosity of p-azoxyanisole. They found that if the molecules
were oriented perpendicular to the walls of a capillary tube there was a
much more pronounced non-Newtonian behavior of the viscosity than if the
molecules were parallel to the walls. Martinoty and Candau21 studied
the viscosity coefficients using shear wave reflectance equations.
Gahwiller22 determined five independent viscosity coefficients using a
combination of the flow velocity and changes in birefringence induced
by laminar flow in a magnetic field. Wahl and Fisher23 looked at shear
flow using rotating glass plates. With this method they were able to

obtain elastic and viscosity constants of N-(p-methoxybenzylidene)-p-

butylamine (MBBA).

Brochard24 studied the effect of rotation of the molecular axis on
some effective viscosity coefficients. He was also able to determine
some of the Leslie coefficients using this technique. Gruler and Meier25
determined the splay and bend constants of a series of 4,4'-di{n-alkoxy)-
azoxybenzenes by means of changes in birefringence of parallel oriented
samples in a magnetic field. Porter et al.26 studied the viscosity of
blends of cholesteryl acetate and myristate. These studies showed that
the viscosity was Newtonian in the isotropic phase, but non-Newtonian
in the cholesteric and smectic phases. DeGennes27 calculated the
effect of shear flows on critical fluctuations in fluids. Kim et 31.28
measured the anisotropic shear viscosity in CBOOA. They found that if
the molecules are aligned parallel to the walls, the smectic phase
showed nearly Newtonian flow, and the temperature dependence had an
Arrhenius behavior.

Karat and Madhusudanazg"31 looked at the elastic properties of a
series of 4'-n-Alkyl-4-Cyanobiphenyls. The constants showed the odd-
even effect. Bata et al.32 obtained rotary motion of liquid crystal
molecules about their short axes from splay viscosity measurements.

The relaxation time showed a Stokes-Einstein type of behavior. Kawamura
and Iwayanagi33 Obtained a complex shear viscosity in the isotropic and
nematic phases of nematic liquid crystals. They noticed Newtonian

behavior in both phases. White et a1.34 measured the apparent viscosity
of MBBA, hexyloxybenzylidene amino benzonitrile (HBAB), and cyanobenzylidene
octyloxyaniline (CBOOA). They showed that the measured viscosities fit

all the standard relations. A good review of the physical properties

of liquid crystals can be found in a book written by DeGennes.35

III. THEORETICAL

In describing the expected shape of a Raman band one must start
from the basic equation that describes the transition between energy
levels, taken from the Schrodinger picture of a molecular transition.
In the Schrodinger viewpoint, the intensity of a Raman band can be

. . . . . 36
written u51ng the polarization formula for non-resonant Raman scattering:
. I V S 2 S I
I(w) = 2p.z|<:|e - a - e |f>| 6(w -w + m + w ~ w.), (1)
. 1 L L . v f 1
1 f -
where i and f correspond to the initial and final rotation-tranSlation_
states of the molecule, respectively. The m's are the frequencies of
the radiation, with: OI the frequency of the incident photon, ms the

scattered frequency, and wv’ w , and mi corresponding to the energies

f
of the vibration, the final state, and the initial state, respectively.
The polarization is given by av, and f1 and ES are the incident and
a
scattered unit, polarized, electric vectors, respectively.
To convert to the Heisenberg picture the first assumption that is

made is that the sample is in thermal equilibrium before each photon

is scattered, so that

-n .5
pi = e i/kT/Ze “i/kT. (2)
i
The delta function in Equation 1 is expressed as a Fourier integral
with the form
on _ t
5(m) = (1/2n) f elfl’dt (3)

10

Using Equation 3, Equation 1 becomes

' S
I(w) = (1/2n)£piX < iIEI . a“ - e |£><fl€I . a” . esli >
i f a : ~ ~ 9 r
m i(wS-w1+w )t iw t —iw t
x f e v e f e 1 dt' (4)

-m

The next step in the transformation is to express the rotation-
translation energies as eigenvalues of the Hamiltonian, H, acting on
the states |i> and ]f>, and to sum over the complete set of final
states. Equation 4 becomes

1(w) = (1/2")Zoiz<ilel° av - ES|5><f|e1”t/“ 51 v V S

. a . 8
1 f 3 “ z ”
xe-th/fili> 7 ei(wS-w1+wv)tdt
=(1/2fl) 7 dte-imtgpi<i‘(61 . av . as) th/h(el . av . as)
m 1 ~ : ~ ~ 2 ~
Xe'ifit/h|i>, (5)
where w = w1 - ms - wv and is the displacement from the center of the

Raman band. Equation 5 can be simplified by using the solution to the

Heisenberg equation of motion
daldt = i(H,a]/fi, (6)

which upon integration with respect to time yields
- A E - . A
elflt/ a(o)e lHt/fi.

~

9(t) = (7)

11

Substituting Equation 7 into Equation 5 yields

v(t) . 85 > e-lwtdt. (8)

~
.

I(w) = (1/2n) I < [81 o av(0) . ES][€I .

I: Q

If the sample is isotropic, Equation 8 can be simplified to

I(w) = (1/2w) f(1/3) < av(0) av(t) > e-iwt

dt. (9)

The factor of 1/3 can be omitted by normalizing the intensity.

To obtain an expression for the time correlation function, the
inverse Fourier transform is taken of Equation 9, and the correlation
function can be written as

¢(t) = < aV(t) av(0) > = f I(m)eiwtdw. (10)

~ -

The polarizability taken into account has been the total polarizability
of the sample. If this is transformed to the polarizability of individual
molecules, the correlation function becomes, when looking at one
component:

D (t) = z < aA (t)aB (O) > (11)

jk B jk jk ,

where the superscripts A and B label the molecules of the system.

Equation 11 can be simplified by expanding Ojk(t) in a Taylor

series in powers of the normal coordinate qv(t),37

_ o + v v +
ajk(t) - ajk(t) iajk(t)q (t) . . . , (12)

where O;k(t) = dajk(t)/dqv(t)[qv = 0. Substituting Equation 12 into
Equation 11 and keeping terms to first order only, the correlation

function can be written as

12

_ 0A OB vA vB
¢jk(t) "' :[<ajk(t)ajk(0)> + i < ajk(t)ajk(0)>

X<q”A(t)q“B(0)>). (13)

where the assumption is made that the internal vibrations are not
coupled to the orientation of the molecule, and thus the cross terms
can be neglected.

The correlation function can be split up into terms that depend
only on molecule A, a "self" part, and into terms that depend on the
interaction between A and B, a "distinct" part.38 When this is done
the correlation function becomes

Ojk(t) = <a?k(t)a?k(0)> :82 < a?k(t)o?k(0)>. (14)

#A
The assumption is now made that the phases of vibrations in different
molecules are random, that is, qvA(t)qu(O) = 0. Using this assumption
and combining Equations 13 and 14, the correlation function can be
written as

Ojk(t) = <a?:(t)a?:(0)> + B:A< a?:(t)agi(0)>

+ z <a§§(t)a§fi(0) ><qvA(t)q“A(0)>, (15)
V

where the three terms are the single-particle Ragleigh, cooperative
Rayleigh, and single-particle Raman scattering, respectively.
Any of the three terms in Equation 15 can be used to extract

reorientational information from a lineshape measurement Of the sample

in question. Since the Raman scattering arises from normal vibrational

13

modes of the molecule, it can be used to probe how different vibrational
modes reorient, and thus, by careful selection of the mode, the
reorientation about the different molecular axes can be sampled.
Therefore, the single-particle Raman scattering term of Equation 15 will
be analyzed. The superscripts denoting the molecule will be dropped
since it is a single—particle process. The terms ng can be separated
into an isotropic part and an anisotropic part. The two parts are,
respectively,

v v

a = (1/3) Iajj’

J

v = v _ v
Bjk ajk a Ojk. (16)

Since the anisotropic part does not commute with the rotational kinetic

39 . . . . . . .
energy, it is this part that contains the rotational information.

Thus the orientational component of the spectrum is:38
OR _ w v v -imt
Ijk - f < sjk(A)ejk(0)>e dt, (17)

.00

where the intrinsic width has been neglected.
In order to extract reorientational information from Equation 17,,
the form of <B;k(t)8;k(0)> must be determined. Viewed in the molecular

frame of reference the B; 's are constants that are dependent only on the

k

. . . . 8
structure of the molecule. Written in spherical notation, they become:3

v _ 1/2 v
80 - ((6) /2)szz,

3:1 = (Imus;z - 13:2).
8:2 = (1/2)(8:x - B;y):is:y. (l8)

14

The molecular frame is different from the laboratory frame and the
relation between the two can be described by a rotation in terms of

Eulerian angles, O(a,8,y).4o The transformation from the molecular

frame to the laboratory frame can be performed by38
2

(2) v
2 Dnm (Q)Bm(MF), (19)

V
B (O) =
,n m=_2

where D£:)(O) is the Wigner rotation matrix of the second order and is

described by41

i"“e‘inYM-lfinjm):(j+n)!(j-m)!(Haul/2

j = -
Dnm(n) e S

XIS!(j'S'H)!(j+m-S)!(n+s-m)l]-1[cos(B/2)]2j+m-n~25

]h-m+Zs

X[-sin(B/2) , (20)

with the sum over 5 Starting where all the factorials in the denominator
are positive. The B;(MF)'S are the spherical polarizability elements
in the molecular frame.

Now that there is a relation between the laboratory frame and the
molecular frame, a laboratory coordinate system must be chosen. Let
the light be incident along the Y axis, and view the 90° scattering along
the X axis. The polarization perpendicular to this scattering plane is
called V and the polarization in the plane H.38 From this arrangement
there are four possible combinations of the incident and scattered
polarizations for the system: VV, VH, HV, and HH, where the first
letter indicates the polarization of the incident beam and the second
letter the polarization of the scattered light. In the laboratory frame

a single element of the polarizability tensor, 8§k(Q), is selected for

15

each of the four spectra. The equations can be exemplified using the

VH scattering geometry. The B;k(O) selected by VH scattering is

V

. V V
eyz(9) = 1[81(Q) + s_1(a)]
- . (2) + (2) v
- 1;[Dlm (a) D_1m(a))sm(MF). (21)

where the appropriate terms are obtained from Equations 18 and 19.
From Equation 21 the time correlation function becomes
V* v _ (2)* . (2)* .
<eyz(a)syz(a)> - in<[D1“ (9 ) + D-ln (9 ))

X[D{;)(O) + Dfi;(n)]82*(MF)Bz(MF)>. (22)

In order to proceed further with the evaluation of the correlation
function one must evaluate the probability that in any time t a molecule
will have rotated through an angle between A9 and A9 + d(AO) from its
initial orientation 9; that is, some form must be given for the single
particle orientational probability density, P(AQ,t). Here the implicit
assumption is that the probability density depends only on the change in
angle and not the initial angle. The probability density provides
information about the reorientational motion of the molecule. In fact,
any experiment that can be devised to gain some understanding about the
rotations will probe P(AQ,t). One possible functional form for P(A9,t)
is an expansion in terms of a sum of products of the Wigner matrices and

an arbitrary function of time, f££)(t).38 P(AO,t) then becomes

16

P(AQ,t) = z D(:)(An)f(£)(t). (23)
2k

The D matrices will operate on one another to give the following

transformation property:

D(2)*

. _ (2)* (2)*
nm (O ) - 2Dn2 (O)ngm (IO), (24)

l

which along with Equation 23 will change Equation 22 into

;(9 )8; :(O)> = 2 (1/81:2 )rded(AO)z k(D(:)(AO)£(“(L)}
mn

(2)* (2)* + (2)* (2)*
X{:'Dln, (Q)Dn,n (LO) D_ln,(O)Dn,n (AO)}

X{D£;)(O) + D(2)(O)}B: (MF)B;(MF). (25)

Upon integration over Q and A9 and application of the orthogonality
condition for the D matrices,41 Equation 25 simplifies to

<8“ (O')sv (n)> = c i I8V(MF)l2f (2)(:). (26)

Y2 Y2 Om____2 m m

Up to this point nothing has been assumed about the molecular
reorientation mechanism. As a molecule rotates in a liquid, the sharp
vibrational transitions seen for an isolated molecule will be broadened
due to the changing interactions with the other molecules in the liquid.
The broadening is therefore characteristic of the liquid and of the
method of molecular rotation. The functional form of the broadened
transition is described by Equation 26, which, as written, is independent
of any choice of model. By selecting a model that is appropriate for
the experimental data collecting technique, Equation 26 can be written
in a form that will yield the reorientational correlation function from

the collected data.

17

Symmetric top molecules are reasonably simple ones to consider
when finding an explicit expression for Equation 26, since fé2)(t) =
ff;)(t). If the major symmetry axis is taken to be the Z axis in the
molecular frame, then f§2)(t) is the correlation fUnction for the
tumbling of the major axis of the molecule. The two functions f£2)(t)
and f§2)(t) contain information about both the tumbling motion and the
reorientation about the major axis. The problem is to determine the
functional form of f£2)(t) by using a model for the reorientation of
the molecule.

For symmetric top molecules there is one feature that makes the
evaluation of f§3)(t) somewhat simpler. Vibrations can be chosen where
only one |B;(MF)|2 # O, and since the IB;(MF)I2'S are the coupling

coefficients for the correlation function, information can be obtained

(2)
f(m)

symmetry of the molecule lets one choose the vibrations which provide

about the (t) that corresponds to the nonzero IB;(MF)I2. The
this information.

The symmetry of the appropriate vibrations very often determines
the form of Bv(MF). Bartoli and Litovitz give a table of the
polarizability elements that are nonzero for the different symmetry
species of the various point groups of symmetric top molecules.38 In
some cases each féz)(t) can be determined separately, but in others
linear combinations of f£2)(t) arise.

The next step in the problem is to assume a model for the rotational
motion. A specific form for Equation 26 has been obtained by assuming

a small-step rotational diffusion model.38 This model is applicable only

to symmetric top molecules. With this assumption Equation 26 becomes

18

2 (2)
\J V _ V 2 9t/
<Byz(9')8yz(9)> - a2 IBmCMF)| e rm (27)
m=-2
where f£2)(t) is expressed as an exponential whose time constant is
(2) _ _ 2 ~l
Tm _ [OD-L + (D11 Dim] (28)

and depends only on the principal rotational diffusion constants of

the molecule. From Equations 28 and 27 the rotational diffusion tensor
can be determined by studying the reorientational spectra of any

two Raman lines that arise from different symmetry vibrations. The
reorientational lineshape is seen to be a Lorentzian function with a
half-width at half-height (HWHH) that is the reciprocal of the
correlation time, TéZ). With these equations, the reorientational motion
about an axis perpendicular to the major symmetry axis and about an

axis parallel to the symmetry axis,38 can be studied.

If, instead of assuming an isotropic medium with small-step
rotational diffusion, the case of an anisotropic medium, where there
exists a preferential molecular orientation, is considered, it is found
that there is a different form for fngz)(t)-2 The difference in form
arises because the rotational motion is no longer random, but there is
a driving force that tends to rotate the molecules back toward an aligned
state. Such a motion leads to a mathematical form for the correlation
fUnction that looks like:

£ng) (t) = Hie-4%, (29)

1

so that Equation 26 becomes

19

v , v _ v . i
<Byz(9 )Byz(9)> - a z le(MF)l Ecie m . (30)

m=~2 1

Since Equation 30 contains an infinite sum of exponentials, the
reorientational lineshapes may be drastically altered. One might
expect that these lineshapes would be non-Lorentzian, and that through
a suitable experiment this change could be detected as the medium
changes from isotropic to anisotropic.

Another way of obtaining reorientational relaxation times is to use
the Stokes-Einstein relation between the shear viscosity of a liquid and
the reorientational correlation time. Bloemberger et a1.42 presented

the following equation for spherical-top molecules:

:2 = 4na3n/3kT; ' (31)

where a is the hydrodynamic rotational radius of the molecule, n is the

viscosity of the fluid, and T is the reorientational correlation time.

2
Equation 31 uses sticking boundary conditions and there has been much
. . . . 43-48 .
discuSSion as to the agreement with experimental data. It is

therefore appropriate to consider the consequences of choosing other
boundary conditions.

Hu and Zwanzig have presented a formulation for calculating a weighting
factor based on the degree of slipping that a molecular system will undergo
as it rotates.43 This slipping gives rise to a relaxation time that is
shorter than that calculated with sticking boundary conditions, so the
weighting factor is less than unity. Alms et al.49951 introduced a non-
zero intercept into the correlation expression to reproduce their
experimental data. This intercept is very similar to the free—rotor

correlation time given by Bartoli and Litovitzl’38 as

20

TFR = 2n(4l/36O)(I/kT)1/2, (32)

where I is the moment of inertia for that rotation.
44 . .
Fury anduJonas obtained an expreSSIOn for T2 of the form

T2(T.n) = C(T)n + tom"), (33)

where rO(T) is the free—rotor correlation time. Applying the slip/
stick ratio obtained from Hu and Zwanzig43 they obtained the following

expression for C(T):
C(T) = (4Wa3/3kT)Oeff’ (34)

where Geffris the effective slip/stick ratio and can be estimated in

three different ways;

Geff.= (1/3)i6(oi), (353)
eeff = (2/3)9(oxy). (33b)
eeff = imi(pi)’ (35c)
where i = (x,xz) and pi represents the deviation from sphericity.
mi is a weighting factor that is given by
“’1 = 03905-1 (36)

1
and is related to an inverse of the area swept out by rotation about the
ith axis. As the molecule becomes more spherical Equation 35c approaches
the value of Equation 35a, so the difference in the two is related to

the non-spherical nature of the molecule and will be reflected in the

21

. . . . 52
resulting correlation times. ASSInk and Jonas have presented another

modification to the Stokes—Einstein relation, which is:
3
12 = (4na n/3kT)fR, (37)

where fR is the rotational microviscosity factor and is equal to
0.163 for a neat liquid.

The expressions derived using slipping boundary conditions work well
when there is a reasonable degree of sphericity to the molecular system.
It is more likely that the behavior of liquid crystal systems will
follow sticking boundary conditions, since they are composed of long,
rodlike molecules. Therefore, the equation used by Gierke and Flygaress
in the investigation of reorientational relaxation of p-methoxybenzylidine-
n-butylaniline (MBBA) was formulated from sticking boundary conditions

and a nonzero intercept. The equation they used was a modified form of

Equation 31,

r = V*n/kT + r0

2 2° (38)

V* is the effective molecular volume and can be calculated from density

0 . . . . . .
measurements and 12 is the zero v15c051ty intercept given by Equation

32.

IV. EXPERIMENTAL

The experimental data were collected using a laser Raman system
built from components to suit a variety of experimental needs.54’SS
Figure 1 shows a block diagram of this instrument. Excitation is provided
by either a Spectra-Physics model 165 krypton ion on a Spectra-Physics
model 164 argon ion gas laser, each permitting a choice of several
excitation wavelengths. The laser emission is sent through a Spectra-
Physics model 310-21 polarization rotator to define the incident
electric vector, and the light scattered from the sample is passed
through a piece of Polaroid film to select the polarization to be
analyzed. The scattered light is then focused onto the entrance slit
of a Jarrell-Ash model 25-100 double monochromator, and the dispersed
radiation is detected by an RCA model C31034A photomultiplier tube
cooled to ~30°C by a Products for Research model TE-104TS thermoelectric
cooler. The electrical output of the photomultiplier tube is sent
either to a picoammeter which detects and amplifies the average current,
or to a photon counting system which counts the number of current pulses
per unit time. The photon counting system can be interfaced to a mini-
computer, and that part of the system will be described in some detail
in the next chapter.

The sample cell used for simple isotropic liquids is shown in
Figure 2. It is fabricated of glass and has Optically flat ends so that
the laser light enters without being defocused by the air-glass or glass-

liquid interfaces. For samples where the temperature needed to be

controlled or monitored, a quartz cuvette of dimensions 7mm x 7mm x 25.4mm

22

23

FIGURE 1. A BLOCK DIAGRAM OF THE LASER RAMAN SYSTEM USED FOR THIS
WORK.

 

5 ------------------------------ LASERI

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

ROTATOR
. PDP
g 11
i PDP
E 8/1
a g ,
mmfl SPECTROMETERL—a PMT
SAMPLE

 

 

FIGURE 1

 

25

FIGURE 2. THE GLASS RAMAN CELL USED FOR SIMPLE LIQUIDS

 

26

<l-—-‘£ Stopper

 

 

 

FIGURE 2

27

was employed. Temperatures near 25°C were maintained by the copper
holder shown in Figure 3. The block is hollow to allow circulation of
a thermostatting liquid. Because of its high heat capacity, water was
normally chosen as the temperature-controlling liquid; it was circulated
by a pump from a reservoir which also contained an immersion heater and
thermostat. The sample temperature was monitored at a slot in the cuvette
holder by means of a copper-constantan thermocouple (see Figure 3).
Raman scattered radiation was gathered from a slit in the copper block.
Figure 4 shows the holder used for temperatures above 100°C. The
optical features are the same as the circulating holder for the cuvette,
but this high-temperature block is solid copper, warmed by means of a
resistive heater. The temperature is controlled by placing a thermistor
in a feedback loop which controls the current to the heater. In both
of the sample holders a glass cover plate is placed over the cuvette.
The data analysis can be simplified by the following definition of
the scattering geometry (see Figure l). The incident laser light is
along the y-axis and the 90° scattered light is along the x-axis. The
polarization of the electric vectors of both the incident and the
scattered light can be related to the xy scattering plane. Polarization
perpendicular to the scattering plane, i.e., in the z direction, is
designated as V polarization; polarization in the xy plane is denoted
as H polarization. Four possible spectroscopic combinations result;1
VV, VH, HV, and HH, where the incident polarization is designated by the
first letter. The VV scattering geometry yields a polarized spectrum,
while the other three scattering geometries provide depolarized

spectra.

28

FIGURE 3. THE COPPER CUVETTE HOLDER USED FOR RAMAN EXPERIMENTS RUN
AT TEMPERATURES AROUND 25°C.

29

00"” Thermocouple

 

Top View

 

 

 

----—-—-—-T

 

 

 

Side View

FIGURE 3

 

 

I I
‘~ .
‘1' It, ‘1
~’1 I l\~.,I

I I

I I

l I

I I

l I

I I

I l

I I

| I

| l

| I

I I

I I

I I

L .J

 

 

 

Front View

 

30

FIGURE 4. THE COPPER CUVETTE HOLDER USED FOR RAMAN EXPERIMENTS
RUN AT TEMPERATURES ABOVE 100°C.

31

 

 

0""- Thermistor

b-‘
Dad

0—P— Thermocouple

 

 

 

 

 

Top View

 

Heater —(b O

 

 

 

 

Front View

 

 

 

 

 

 

Side View

FIGURE 4

32

In order to obtain meaningful lineshape measurements, the
resolution of the monochromotor was set at a spectral slit width of
1.0cm-1. The dispersion of the monochromator varies with absolute
frequency, but over a small interval (less than lOOcm‘l) the dispersion
does not vary sufficiently to change the spectral slit width signifi-
cantly. The resolution was chosen to be roughly five to ten times
smaller than the half-widths of the isolated Raman bands that were
analyzed. In order to obtain enough data points to properly define
the overall shape of a Raman band, the sampling interval was chosen
to be 0.05cm-1, or one step on the monochromator stepping motor. The
range of a scan was 50cm'1, or 1000 data points, chosen as the optimum
compromise between computational time on the CDC 6500 computer and
determination of the lineshape in the wings of a Raman band. The
limiting factor in this decision was the core size of the CDC 6500
computer (150K octal words).

The instrumental function was measured by using a candle to
scatter the incident radiation. A non-lasing fluorescence transition
of the argon ion plasma was chosen. With the laser in resonance at
5145A, the plasma line at 4880A was viewed. Since this electronic
transition is essentially a delta function, the only contribution to the
overall shape is due to the instrument function. As with the sample
data, the Slit width was 1.0cm"1 and the range of the scan was 50cm"1

Density measurements were made using a 1.0 m1 pycnometer. Since
changes in weight were observed in the 10-100 mg range for neighboring
temperatures, the sample was weighed four times on a Mettler 0.1

milligram balance to obtain an average weight. Pure water was weighed

33

at the same temperatures to correct for expansion of the pycnometer.
The viscosities were measured with a Cannon Instrument Company Ostwald
viscometer, number 75/K280, which has a flow constant of 0.00794
centistokes/second. An average of two runs was used to obtain the
flow times. The viscometer was kept at a constant temperature in a
water bath with a blade heater and a thermoregulator. For both the
density and the viscometer water baths the temperature was controlled

to 30.1°C.

V. INSTRUMENTAL

With the greater availability of minicomputers and micr0processors
it has become apparent that interfacing a Raman spectrometer to such a
device has many advantages.56”58 One such advantage is the ability to
utilize multiple scans or longer integration times, thus increasing
the signal-to-noise ratio (S/N) and thereby extracting weak signals from
the background noise. Another advantage is the ability to perform
repeated, sequential scans of a region of the spectrum and consequently
to follow the time development of the system. Also, any data analysis
that must be performed on a large region of the spectrum.such as line-
shape fitting, is easier and more convenient if the data are collected
in digital form in real time.59

The computer interface between Digital Equipment Corporation
PDP 8/1 or PDP 8/M minicomputers and the Raman instrument described
previously, designed and constructed as part of this dissertation work,
is outlined in Figure 5. The interface consists of six circuit cards
in a Vector card cage. The cards are located in slots two through seven,
counting from left to right as viewed from the front of the cage. The
cards cannot be interchanged in the cage, since the wiring on the back
connectors differs depending on the particular slot. The interface
comprises three distinct parts: photon counter, stepping motor, and
control logic.

The photon counting portion consists of two lZ-bit counters with

an overflow flag on each counter. This allows up to three 12-bit

words (235 pulses) in the minicomputer to be used to count the number

34

35

FIGURE 5. THE OVERALL SCHEMATIC OF THE INTERFACE BETWEEN A PDP 8/I
MINICOMPUTER AND A JARRELL-ASH RAMAN SPECTROMETER.

36

 

 

“I
Inca .
("I . I Ll
, 12 m , 12 III .
. I comm ’— cmm '
|

 

 

 

 

5

5 7“ . .‘li.’ '
I 0

0

II
I"

.I

'7

FIGURE 5

 

 

FEE

 

   

37

of photons striking the detector, thus enabling longer integration times
before the counter overflows. The stepping motor control connects the
minicomputer to the RTL electronics in the Raman instrument stepping
motor control circuitry. It consists of a flip-flop (the output level
defining the direction of motor rotation) and a monostable multivibrator
that shapes the pulses used to drive the stepping motor. A capacitor
and a resistor connected to the monostable limit the pulse rate to less
than 400Hz, thus insuring that the stepping motor control will not become
overloaded and start skipping steps. The control logic is used to sample
the contents of each lZ-bit counter separately, clear the counters,

check the overflow flags, run the stepping motor, and turn the counter

on or off. The inpUt pulses to the control logic and the contents of

the counters are transported between the minicomputer and the Raman
spectrometer along two 70 foot, 34 line, ribbon cables with every
alternate line connected to common. The +5 volt signal from the
interface power supply is also sent along the ribbon cable to activate
the line receivers connected to the minicomputer bus line.

The data acquisition programs are listed in Appendix A and a flow-
chart is provided in Figure 6. Some of the subroutines used, but not
listed in Appendix A, were obtained from E. J. Darland.60 The run-
time parameters are defined in an interactive mode. First the minimum
count time, which fixes the time the counter will be open for an initial
measurement of the strength of the signal, is set. A calculation is
then performed on the initial count rate to determine whether the preset
number of counts (chosen to attain a certain S/N) will be reached within

the preset maximum count time interval. Usually 0.1 to 0.2 seconds is

38

FIGURE 6. A FLOWCHART OF PROGRAM DATCOL.SV

 

139

 

SET
TITTTAL
PAIAIETEOS

 

OOOIT FOO
CALOOLATED

TTIE

 

 

 

 

 

CLOSE
DATA
FILE

 

STORE
DATA
POINT

 

 
   
   
 

IITEBBOPT
RAISED?

IDTE
ODATIIO

 

 

 

 

 

L, menu:

 

I

DOOITSISEO ‘

 

L___,

   
     
   
  
   
   
   
 

OE OBATTI
BACK TO

POINT

RESET
PARAMETERS

 

FIGURE 6

SIAAIIIG ‘

 

 

 

 

 
  

 

OHAII TO
OOOICH.SV

DflAll TO
IOVE.3'

 

1 STORE
DATA

 

40

sufficient for the initial count time. The next parameter to be set is

the maximum count time, the longest interval for which the counter will

be open to collect the pulses from the photomultiplier tube at a given

data point. Longer count times will allow weaker signals to be

detected and separated from the background noise. A count time of one

to five seconds is adequate for a long survey scan, but count times up

to forty seconds can be used to collect very weak signals. Next the

limits of the scan are entered. Both the starting point and the ending

point are entered as Stokes shifted frequencies (AC'S) in wavenumbers.
Next the total number of counts desired is entered. This determines

the signal-to-noise ratio that will be obtained during the run, since

for random noise the S/N is the square root of the total number of counts.

Usually for a quick survey run the number of counts entered should be

between 1000 and 5000, depending on the background level. The total

number of counts is coupled with the maximum count time, and care must

be taken to set the two so that the background is not treated as part

of the Raman signal and thus integrated for a long period of time. This

is done by setting the maximum number of counts high enough so that the

background counts will never reach that number within the maximum

count time. If the background is treated as part of the Raman signal

the quick survey scan could last for a few hours. For higher

resolution scans over a small region of the spectrum, 10,000 counts

or higher is adequate, depending on the strength of the Raman signal.
The next parameter to be entered is the spacing between data points.

1

Since each step of the stepping motor moves the spectrometer 0.05cm' ,

the spacing entered must be a multiple of this number. The spacing

61

41

should be chosen so that an adequate number of data points, usually

four or five, is collected per spectral slit width. The next parameter
set is the number of scans desired over the region of interest. This
enables the Operator to collect many data sets for signal averaging
without having to reenter the input parameters. Next the strip chart
recorder parameters are setq These are maximum counts per second and
wavenumbers per inch. Both parameters are selected according to the
operator's discretion regarding the data display in real time; they have
no influence on how the data are collected or stored. For example, if
the pen goes off scale the data are still stored by the computer as
collected. Finally the filenames are entered in the form DEVI:FINAME,
where DEVI is a standard OS/8 device name (RKBl, FLP2, DTAO, SYS, etc.)
and FINAME is a six character file name. An extension of .DA is
automatically appended to the filename.60 If it becomes necessary113
change parameters during a data run the program can be interruptedbe
striking a CONTROL G (*G) on the terminal. If the program is continued
it will ask the operator which parameters he or she would like to change.
Following this pause the program will continue to collect data.

After the run-time parameters are entered the program opens the
counter for the minimum count time and samples the counters. The
computer then performs a calculation to determine if the predetermined
number of counts will be reached within the specified integration time.6
If this condition is not met the program will store the counts/second
calculated and then step the motor to move the grating the preset distance.
If the above condition is met, the program will calculate how long the

counter should be active to reach the predetermined number of counts.

42

Once this is done the program opens the counter for that calculated length
of time, samples the counter, calculates the counts/second, and steps
the stepping motor. If the predetermined number of counts has been
exceeded in the initial count period, the computer will calculate the
count/second and step the stepping motor. After each step there is a
software wait loop of about five milliseconds to let the moving parts
settle down and also to keep the electronics from becoming overloaded.
The data are stored as counts/second versus Stokes wavenumber in A6
format on a mass storage device, the choice being a hard disk, floppy
disk, or Dectape.

Before the data collection is initiated, the spectrometer should
be positioned at the desired starting frequency. This is accomplished
by a program called MOVE, which is listed in Appendix B; the flowchart
is given in Figure 7. This program will direct the stepping motor to
move the grating of the Raman Spectrometer from one frequency to another,
and will also calibrate the system by scanning over the laser excitation
line. The spectrometer must first be positioned about five wavenumbers
to the blue of the excitation wavenumber and precautions MUST be taken
to insure that very little light strikes the detector. This is done by
setting the laser output power at 100 milliwatts, the voltage on the
photomultiplier tube at 1100 volts, and the slits at 10-20-10 microns.
The computer then scans the grating through the excitation frequency,
collects the counts/second, and finds the maximum signal. The position
of the maximum is defined as zero and is used as the reference point
for the Stokes-Shifted Raman scattering. The computer then inquires of
the operator the starting wavenumber shift for the Raman scan and moves

the spectrometer to that point.

43

FIGURE 7. A FLOWCHART OF PROGRAM MOVE.SV

 

44

 

LI

 

 

YES
, IIIII om
:gflfg, I EXCIIAIIOI
FBEOOEICY

 

 

 

O

 
   

  
 

 

 

 

 

   

   
     

 

 

 

 

SET
o;:¥¥i‘ -t-—-~ naxxnou
IO zrlo
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o
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O

  
 
 

  

IOVE
ORAN“?

 

 

  

FIGURE 7

45

The data are analyzed with a PDP 8/1, a PDP 8/M, or a CDC 6500
computer. The PDP 8 programs are listed in Appendix C and a flowchart
is provided in Figure 8. These programs include baseline correction,
smoothing, normalization of individual bands, peck location, signal
averaging, and plotting of data on either a CRT display terminal or a
strip chart recorder. The programs are all designed to use a minimum
number of core locations, and are therefore somewhat slow when operating
on a large amount of data.

The baseline correction program assumes a linear baseline function
and performs a least squares fit of a preset number of data points to a
general straight line equation.62 The calculated straight line is
then subtracted from the entire data set and the new data are stored in
another file.

The smoothing routine uses a l7-point polynomial fit to calculate
a better value for the central point. The weighting coefficients
incorporated in the program were derived from a table published by
Sovitzky and Golay.63 The smoothing routine should be used with caution,
since some distortion arises from any type of data smoothing.64
Smoothing will make the Raman bands look sharper and will thus enhance
any parameters that are extracted by way of human interaction, such
as obtaining peak locations from a plot of the spectrum.

The normalization program scales the entire Raman spectrum so
that the maximum intensity of the strongest band in the desired region
is assigned a value of unity. This routine is useful for preparing the
data for bandshape measurements, and also can be used to scale spectra

for background subtraction, enabling changes in relative band intensities

under varying experimental conditions to be easily discerned.

46

FIGURE 8. A FLOWCHART OF PROGRAM CRUNCH.SV

BET
TIPOT
PABAIETEBS

 

 

 

 

 

    

 

 

 
  
   
   
 

 

 
 

417

  
    

  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

  

 

 

 

 

 

 

CBAII to
novs.sr
no
cauucn x'Iii'v
v CflAII to
collect YALOES
no
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roanar
cross
IAIA
rsts
I
cum III
sieav.sv
CDAII to susrnncr SE! urn
snooru.sv OASELIIE nonnarrz: PABAIETEHS

 

  

 
 
   

 

FIGURE 8

 

 

 

 

 

 

90494

POTIT?

SIOIAL
AVEDAOE?

 

48

The peak location routine finds all the local maxima above a preset
level within a specified region of the data file. The program checks
whether the difference between the maximum and minimum values within
a twenty point region around the maximum is greater than the signal-to-
noise ratio. If the difference is not greater, then the maximum is really
part of the background. Also the maximum must be the central point in
the twenty point region. Twenty points were chosen as an adequate trade-
off between finding all the shoulders and sidebands and rejecting
noise spikes in the background.

The signal averaging routine will either add or subtract data files.
Up to 100 data files can be added together to improve the signal—to-noise
ratio. The subtraction feature is useful to remove the effects of
background and solvent bands.

The data plotting routine plots all or part of a data file on
either a Tektronix model 4010 terminal or a strip chart recorder. The
program first scans the region to be plotted to find the extrema within
that region. If the plot is to be on the terminal the program will
ask the operator to choose either point or line plot options. It also
asks for the tick interval on the x-axis. When the file is plotted
out crosshairs appear. The x and y values of the intersection of the
crosshairs are printed when any key is struck. To exit this part of the
program a CONTROL G (“6) must be struck. If the plot is to be on the
strip chart recorder the program asks the operator to input the spacing
on the chart in wavenumbers/inch.

Another option in the package is a routine that will take the data

files from the format used for storage on the PDP 8's (A6) and translate

49

the numbers to a standard format (E15.7). The transfer can be made with
a two character data tag placed at the beginning of each line of data.
Once the data are in the E format they are in a form suitable for use

on the Cal Data 135 minicomputer in the CEMCOMGRAF facility. This
minicomputer is configured like a Digital Equipment Corporation PDP 11
and uses the same software. The Cal Data 135 computer has a phone line
interface with the University's CDC 6500 computer, and the data files
are transferred between them as batch jobs.

The data analysis programs used on the CDC 6500 computer are
lineshape determination programs. They are listed in Appendix D and the
flowchart is shown in Figure 9. These programs were obtained from D. A.
Wright65 and modified to suit the Raman data obtained in this dissertation
work. The rotational lineshape is assumed to be a Lorentzian fUnction
and is convolved with the isotropic line and fit to the anistotropic
line. The convolution is performed as a Simpson's rule integration, and
the fit is made by a least-squares method of minimizing the sum of the
squared residuals between the calculated and experimental functions as
the half-width of the Lorentzian function is varied. The final results
of this program are sent back to the Cal Data 135 minicomputer for diSplay
on a matrix plotter. To obtain the vibrational function only minor
modifications were made to the programs.

Sometimes instruments and electronic components seem to have minds
of their own, and it becomes necessary to perform some troubleshooting.
For the Raman system described in this dissertation experience has shown

that several of the problems that may arise can be solved fairly readily.

50

FIGURE 9. A FLOWCHART OF PROGRAM LNSHP.

 

 

 

 

 

51

 

PLOT
RESULTS

   

 

 

 

 

 

 

 

 

 

 

 

 

 

RIIIROR
ERROR?

 

FIT TO YR
AND FIND
ERROR

 

    
   

 

 

 

 

 

I

CHARGE
RALFIIDTR

 

 

 

CORVOLV
VV RITR
LORERTZIAR

 

 

 

 

 

 

 

 

I

 

 

NORRALTZE

 

 

no
es
READ
INPUT
PARAREIEBS
P *
READ
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FIGURE 9

 

 

 

 

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CORRECT FOR

POLARIZATTO
LEAKAGE

 

 

52

One such problem is the stepping motor not taking the specified number
of steps. A symptom of this problem is the program not returning the
spectrometer to the correct starting frequency. The step line leading
from the interface to the spectrometer is the first place that an
oscilloscope should be inserted to check out the system. The following
diagnostic program should then be toggled into the minicomputer from

the switch register:

0200 6616
0201 7604
0202 7001
0203 7440
0204 5202
0205 5200

This program will send pulses to the stepping motor at a rate that is
determined by the setting on the switch register. To run the routine
just below the limit of the monostable multivibrator the switch

register should be set to 2000 The pulses should be regularly

8'
spaced with no jitter when viewed on the oscilloscope. The usual
source of step line problems is either a faulty flip-flop or monostable
multivibrator on the card in slot seven of the cage.

If the step line is working well, the problem might be in the level
line which controls the direction of the spectrometer. This can also
be checked with an oscilloscope. The following little program will
test the level line circuitry:

0200 6614

0201 6615

0202 5200

53

This routine will change the state of a flip-flop on card seven and cause
the output to be a series of pulses that should be jitter-free when
viewed on the oscilloscope. The jitter that has been seen in the past

at this flip—flop has resulted from some high frequency noise on the
inputs to the flip-flop. The noise was coming from some partial

solder bridges on the circuit card. Also, at one time the unused inputs
of the flip-flop were not properly terminated.

Sometimes one of the counters will be stuck in one state, or an
integrated circuit associated with the counters might fail. To test the
counters, a pulse generator is placed at the count input to the inter-
face cage, either program from Appendix E is toggled into the computer,
and the AC display on the computer is monitored as it counts up. If the
circuitry is not counting properly, the malfunctioning bit can be
retraced through the interface circuitry until the problem is spotted.
If both programs Show that the same bit is malfunctioning, the problem
is probably in the final latch circuitry. If a bit is not working
properly on only one program, then the problem is on the appropriate
counter card.

Occasionally problems have arisen due to a difference in ground
connections between the interface cage at the Raman instrument and the
interface cage at the computer. These differences will set up a ground
loop that can cause enough noise on the ribbon cable to degrade the
signals. Ground loops are sometimes very difficult to trace down and
solve,66 but in the past just a simple switch of a power cord from one

outlet to another has worked.

VI. LINESHAPE ANALYSIS OF SIMPLE LIQUIDS

The reorientational lineshapes of several simple, isotroPic liquids
were measured to serve as standards for the lineshape analysis of an
anisotropic system. Acetonitrile (CH3CN) and chloroform (CHC13) were
chosen as the sample liquids, and the computer programs written to
collect and analyze the data were tested on them. These liquids have
been subjects of many experiments, and there are sufficient results in

1’38’48’67-70 The method of

the literature to enable easy comparison.
analysis chosen was similar to that used by Bartoli and Litovitz in
their analysis of polarized Raman bands.1

The liquid that gave the best results was acetonitrile. Its Raman
spectrum is shown in Figure 10: The band that is the easiest to
analyze is the CEN stretch at 2250 cm-1. This is anAx1 vibration and
is strongly polarized. Figure 11 shows the isolated vibrational band
that was used as input for the lineshape analysis program described
previously. The peak labeled P is the polarized scattering, and that
labeled D is the depolarized scattering. The crude depolarization ratio
for this band was measured to be 0.070. After correction for analyzer
efficiency and polarization leakage the depolarization ratio became
0.057. The results of the lineshape calculation are shown in Figure 12.
The peak labeled D is again the depolarized scattering. The curve
labeled C is a convolution of the polarized scattering and a Lorentzian
function used to approximate the reorientational correlation function.

The program, which ceases iteration when the half-width change in two

successive cycles is less than 0.01cm-1, converged to a reorientational

54

55

FIGURE 10. SURVEY SCAN OF THE RAMAN SPECTRUM OF ACETONITRILE

56

 

u»
a
o.
.u
a

°.-. - .s 3 .° 3...:- :. -

‘v-.. U.

o..-

.0 0’ '00... o 0...: 3..

a. 00 ‘ 9°‘00'o

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A

H

OH mmsomm

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mqmeHZOHmU<

mouoaeomfla b
4
P
--
)-
I
b

OOH

o.o

puooas/siunog

ooom~

57

FIGURE 11. THE 2250 chl VIBRATIONAL BAND OF ACETONITRILE, USED

AS INPUT TO PROGRAM LNSHP.

5000

Counts/Second

0.

0

58

2250 cm'1 band of CH3CN

Jillllllll'llllIlllllllllllllllllllllllIJ

 

LIIILIJI

 

 

TIT[ITIVWIIITIIITITlTIlTTITITlTTiTTIrITrlIIITFTTVY—l

2220 2270

Wavenumber Shift (chl)

FIGURE 11

59

FIGURE 12. THE OUTPUT OF PROGRAM LNSHP FOR THE 2250 crn_l VIBRATIONAL

BAND OF ACETONITRILE.

60

2250 cm‘1 band of CHSCN

1.1“

Relative Intensity

 

 

‘0.1 TIIT.TTTTIIIITIITITrllrlrIIITr'TITITTTfrlTTTIITITT]

2220 _1 2270
Wavenumber Shift (cm )

FIGURE 12

61

half-width of 3.0 t 0.5 cmul. This number compares favorably with the
half-width obtained by Bartoli and Litovitz using the same experimental
and computational methods (3.5 cm-l).1 The reorientational lifetimes
calculated through T = l/(ZUCWOR), corresponding to an W0R of 3.0 cm"1 is
1.8 i 0.3 psec. This may be compared to the value Patterson and
Griffiths obtained from depolarized Rayleigh scattering (1.8 psec).69
Whittenburg and Wang obtained similar results in a more recent work from
half-widths of Raman bands.48

The analysis program was debugged and characterized using
acetonitrile and other simple liquids. Some of the pitfalls that were
observed while using this technique will be discussed in a later chapter.
It should be noted at this point that the technique is very sensitive
with regard to the strength of the transition being analyzed. Although
this is true of most forms of spectroscopy, the effeCts become even

more apparent when one is dealing with a quantity that results from the

difference of two very similar experimental measurements.

VII. LIFETIME STUDY OF LIQUID CRYSTAL SYSTEMS

As was noted in the previous chapter, much work has been done on
lineshape analysis of simple liquids, where the overall environment is
isotropic and the reorientational bandshape is Lorentzian. It is
possible that different theoretical predictions apply when the overall
environment is anistotropic, as was shown in Chapter III. In order to
test this prediction experimently, a suitable choice of an anisotropic
environment must be made. Liquid crystals offer both isotropic and
anisotropic media, depending on the temperature chosen.

The liquid crystal systems utilized in this study all have a
nematic phase, that is, a phase where the long molecules line up like
rods. This means that there is a preferential direction in the liquid
system, while random disorder remains along the other two axes. Since
any nematic liquid crystal could be used to provide an anisotropic
medium for Raman bandshape analysis, some choices must be made, based
upon work in isotropic liquids, in order to attempt to understand what
is happening in the nematic liquid crystal phase. One consideration is
whether to use a vibrational band of the liquid crystal itself, or to
use some probe molecule to sense the environment. Both types of line-
shape measurements have been made in this work. Another requirement is
to find a suitable band that is isolated from other vibrations, and if
it is a vibration of the liquid crystal molecule, to select one that is
not significantly coupled with Other vibrational modes. A third
consideration is the temperature range of the phase transitions. The

three liquid crystal systems that were studied are:

62

63

p«[(p-ethoxybenzylidene)-amino] benzonitrile (EBB), 4-cyano-4'-
pentylbiphenyl (SCB), and n-(p—methoxybenzylidene)-p—butylamine (MBBA).
Their structures are shown in Figure 13.

Work was first attempted on n-(p-methoxybenzylidene)—p-buty1amine
(MBBA); see Figure l3—C. Figure 14 shows the Raman spectra of MBBA in
both the nematic liquid crystal (bottom) and isotropic liquid (top)
phases. This molecule seemed ideal for use as an anisotropic environ-
ment for a suitable guest. Since there is no host scattering around

2200cm-1, acetonitrile (CH CN) was chosen as the guest. Unfortunately,

3
addition of very little acetonitrile (five percent by volume) was
enough to effectively break up the liquid crystal order. At that
concentration the liquid crystal phase covered a span of only 0.S°,
from 15.0° to 15.5°C. At higher concentrations no nematic phase could
be observed, and at lower concentrations the GEN vibrational
scattering from acetonitrile was hidden in the background fluorescence
of the liquid crystal. Even at the five percent concentration the
acetonitrile peak at 2225cm'1 was difficult to discern above the
background. Since the probe molecule produced such a weak signal on
top of fairly strong fluorescence, even data collected for long
periods of time (two days for each polarization) still contained so
much noise that the lineshape analysis program would not converge.
This method might prove fruitful under different conditions, as will
be outlined in the next chapter.

The second liquid crystal system chosen, commercially available

from Kodak, was p-[(p-ethoxybenzylidene)-amino]—benzonitrile (EBB),

shown in Figure l3-A. It was selected because it has a CEN group at

64

FIGURE 13. STRUCTURES OF EBB, 5CB, AND MBBA

65

H

H5C2—O-..—C\:N__C:N

p-[(p-EIhoxybenzyIidene)-ominol benzoniIriIe

H,,C5-. -. -C':';N

4-cyono—4LpenIbeiphenyl

H
H3CO -..—C\:N--C H
4 9

N-(p-methoxybenzylidene)-p-butylomine

FIGURE 13

66

FIGURE 14. SURVEY RAMAN SPECTRA OF MBBA. TOP: ISOTROPIC PHASE
(45°C). BOTTOM: NEMATIC PHASE (25°C)

MBBA

no 0.” an... ' a..00. OQDWOW .50.. "" U".\'¢O

1.1

67

d;

I

.0 .

KitsuaiuI aAtiEIau

 

 

O
O
O
V
r-x
H
l
E
U
V
H
(4.4
-r-1
4:
U)
s...
Q)
.0
E
:1
C
CD
>
(U
3
O
O
H

FIGURE 14

68

one end that has a stretching mOde which is not strongly coupled with
any of the other vibrational modes. Unfortunately, this particular
molecule was not very well suited for lineshape analysis because its
high fluorescence background almost completely washed out the relatively
weak C;N stretch scattering.

The next molecule chosen was 4-cyano-4'-pentylbiphenyl (SCB),
shown in Figure l3-B. This molecule turned out to be the most suitable
of the systems chosen. The published Raman spectra of both the
unsubstituted and the deuterated compounds showed that the CEN stretch
was strong and isolated.19 The greatest problem with this compound
is that it is not readily available. It was therefore necessary to
synthesize SCB before any spectroscopic measurements could be made.

The synthesis was carried out using a modified procedure based on

71 72

preparations published by Gray et a1. and by Sadashiva and Subba Rao.
The first step was a Friedel-Crafts reaction between 4-bromobiphenyl
and pentanoyl chloride to give 4-bromo-4'-pentanoylbiphenyl:

AlCl
3
C4H9COC1 + C6HS C6H4Br ------ C4H9CO C6H4 C6H4Br. (39)

The melting point for this product was 95.S° - 96.S°C which was
considered close enough to the published melting point (98°C) to
continue.71 Next the carbonyl group was reduced with lithium aluminum
hydride in an eighteen hour reflux, with a mixture of diethyl ether and

chloroform used as solvent, to yield 4-bromo-4'-pentylbiphenyl:

AlClS/EtZO
CHCO'CH'CHBr ----------- CSHll°CH'CHBr (40)

4 9 6 4 6 4 LiA1H4/CHC13 6 4 6 4

69

To be certain that the isolated compound was the correct one, the
infrared Spectrum of the product was taken and no carbonyl band was
observed. The melting point of the compound was 90° - 92°C

(literature value 95° - 96°C).71

The third and final step was a
substitution reaction whereby the bromine was replaced with a cyano group.
This was accomplished by reacting the product from the previous step with

cuprous cyanide:

CSH11 ' C6H4 ' C6H4Br + CuCN -—-- CSH11 ' C6H4 ' C6H4CN + CuBr. (41)

After purification by means of column chromatography, a Raman spectrum
of the compund was taken to verify that it was the desired material,

SCB. Figure 15 shows the Raman spectra that were obtained, and they do
match the published spectra of SCB very well.19 The three traces, from
bottom to top, are the solid (15°C), nematic liquid (25°C), and isotropic
liquid (45°C) phases.

In the spectra of Figure 15, note that the CEN stretch, at 2225cm-1,
is a strong, isolated band and is therefore suitable for lineshape
analysis. Another feature, not observed by Gray and Mosley because
of experimental limitations,19 is the C-H stretching region between
2900 and 3200cm'l, which gives the appearance of a plateau because of
the many overlapping bands arising from the different types of C-H
stretching modes in SCB. The survey spectra show that this molecule
does not have the high background scattering that plagued the other
two liquid crystal systems.

Figures 16 and 17 show the raw data from the 2225cm'l scattering

used for the rotational and vibrational lineshape analysis. As with

70

FIGURE 15. SURVEY RAMAN SPECTRA OF SCB. BOTTOM: SOLID PHASE (15°C);
CENTER: NEMATIC PHASE (25°C); TOP: ISOTROPIC LIQUID
PHASE (45°C).

SCB

1.3

71

“calm

~04... o-umcooooo co .0 0‘ 5.0.0.” “Un'l'm9mmm "“ )“N’MT

u-ouooao‘ new " ‘ '-

 

mwm'n: "'

Kitsuaiul antletau

 

, .,v .. e.--—.—-

'. > - a

 

' ..A_ _~.—~-—«-<

0.0 L"-

4000

Wavenumber Shift (ch1)

100

FIGURE 15

FIGURE 16.

2225cm-

1

72

SCATTERING FOR SCB IN THE NEMATIC PHASE (25°C).

 

73

SCB CN Stretch
N-phase

1300

: l
.i ‘.
I i
0 C
’ P
. ‘.
3 s
I '2
f 3
, a
I s '.
3 '2
f :
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IR 3 .
+5 :‘
3 :
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.1"- , a
o . 5.
:1; V
: v.73“! \ V-
" . . SS
8 ‘ z . o x. q \o

0.0

 

[ITIIITITITINTIIrrTIITTTITITTIIITTTTTrTITITTTTTFZTa4S

2195

Wavenumber Shift (cm-1)

FIGURE 16

74

1

FIGURE 17. 2225cm- SCATTERING FOR SCB IN THE ISOTROPIC PHASE (45°C)

O\
C)
C)
C)

l

Counts/Second

0.0

lllLlllllllJJllllll'lIllll]!ILALIllllugldlullllll[JilllILIIll]!

7S

SCB CN Stretch
I-phase

 

 

 

TTIFTTTTTITTTITIIITITTTTTTTTTITTTTTITlll'fiT—TTTITTTI

2195 1 2245
Wavenumber Shift (cm- )

FIGURE 17

76

the simple liquids, the line labeled P is the polarized scattering and
D is the depolarized line. Figure 16 depicts the nematic phase (25°C)
and Figure 17 shows the isotropic phase (45°C). The instrumental
function required for the vibrational lineshape analysis is measured
from a plasma fluorescence line, and is shown in Figure 18, with the
frequency axis shifted to correspond to the SCB 2225cm.1 line. The
depolarization ratio, after corrections for detector efficiency and
polarization leakage are made, is 0.28 for the nematic phase and 0.36
for the isotropic phase. These values, which are larger than that for
the 459 cm.1 band of carbon tetrachloride, indicate that the vibration
is not completely symmetric.73 This means that the center of mass of
the vibration moves with respect to the center of mass of the molecule
during a vibrational period.

The fit of a convolved Lorentzian with the polarized line to the
depolarized line for the isotropic phase is shown in Figure 19. The
apparent frequency shift is an artifact of the display portion of the
computer program used for the convolution and has no bearing on the
results. The Lorentzian function has a half-width of 0.19 t 0.10 cm-l,
corresponding to a reorientational correlation time of 28 1 15 psec.
The corresponding fit for the nematic phase is shown in Figure 20.

In this phase the Lorentzian has a half-width of 0.13 i 0.10 cm-l,
corresponding to a reorientational correlation time of 41 i 30 psec.
Note that the fit for the nematic phase data is not quite as good, which
could be due to the true reorientational function being a sum of

Lorentzians rather than a single Lorentzian. However, the experimental

error is so large that one cannot critically evaluate this possibility.

77

FIGURE 18. INSTRUMENT FUNCTION FOR THE JARRELL-ASH SPECTROMETER:
Ar LASER PLASMA LINE AT 4850A.

78

1100 -

Counts/Second

 

 

O
. O O
.‘ .
O
.1 .
A- k A A M... “A“ AW ‘ . O
Vvvvv‘
'0‘", ‘r—C ‘Vw 1 "v“.I-ww“ '3'. '7 .

0'0 TITTTITI[[lllTTTTTIITITTIIITTI'TITTTITTT'ITIIIITT

2195 2245

Wavenumber Shift (cm-1)

FIGURE 18

79

FIGURE 19. LINESHAPE FIT FOR THE 2225cm-1 RAMAN BAND OF SCB IN

THE ISOTROPIC PHASE (45°C).

1.1

Relative Intensity

-0.1

80

SCB CN Stretch
I-phase

 

 

‘TITTITTTT'TTT—TTIT—rIIrTIFTITVTITIITTTWTTrrrTTTTTTTI

2195 2245

Wavenumber Shift (cm-l)

FIGURE 19

81

FIGURE 20. LINESHAPE FIT FOR THE 2225cm'l RAMAN BAND OF SCB IN
THE NEMATIC PHASE (25°C).

 

 

1.

1

Relative Intensity

-0.

1

82

SCB CN Stretch
N—phase

FTVTIITFT'ITfTTTIITTTTIITTTVTTTITTITTTTIIVTTITTIT

2195

FIGURE 20

flea... ' "WA-3.3m.

Q o
eoo‘eoo. . .
.,...'U :’0.0.:.....’.. . ‘

a“.
00. .00
‘0“...0..::?.:: u o.. .~
00...... o o
.00..

"' c
t:.:.:-~.,

2245

Wavenumber Shift (cm-1)

83

Even though the numbers appear to fall within the common error range,
the student t-test74 indicates that they are statistically different.
Since the overall correlation function for large molecules is
dominated by vibrational relaxation,7s the Vibrational correlation
time for SCB in each liquid phase was calculated by convolving a
Lorentzian fUnction with the instrument function of the Raman spectro-
meter described earlier, and then fitting the resulting function to
the vibrational scattering (the polarized band). Figure 21 shows the
results for the isotropic phase (45°C) of SCB. The Lorentzian half-
width is 3.7 3 0.3 cm-l, corresponding to a vibrational correlation
time of 1.4 3 0.2 psec. Figure 22 shows the result for the nematic

phase (25°C) of SCB. The Lorentzian half-width for this phase is

l+

3.9 0.3 chI, also corresponding to a vibrational correlation time of

I+

1.4 0.2 psec. It is not too surprising that the vibrational relaxation
time for the two different phases is the same, since the local
environment does not change a great deal on either side of the phase
transition.3

When this work was started it was hoped that the local environment
would change enough during a phase transition to produce a significant
change in the reorientational correlation times and functions. It is
possible that such a change did in fact take place, but the
experimental error was large enough that the change could not be
detected by the method used. Perhaps another method could be used
that would give results with less error, and some possibilities will

be discussed in the next chapter. It is also possible that another

approach might be useful both as a check, and as a way of extracting

84

FIGURE 21. VIBRATIONAL LINESHAPE FIT TO THE 2225cm-1 RAMAN BAND
OF SCB IN THE ISOTROPIC PHASE (45°C).

 

 

1.

Relative Intensity

-0.

1

l

85

SCB CN Stretch
I-phase

 

 

 

TTUTT—TITT'rIIllTTVTITTlT—rjilIlTlTTIflTIIITITTTTTT'

2195 _1 2245
Wavenumber Shift (cm )

FIGURE 21

86

FIGURE 22. VIBRATIONAL LINESHAPE FIT TO THE 2225 cm.1 RAMAN BAND

OF SCB IN THE NEMATIC PHASE (25°C)

-O.

87

SCB CN Stretch
N-phase

1.1 '-

3 E
-‘ :‘s 3.
~ :5 P
a: a
:3 :.
_. :5 Q
a: 1"
‘1 P: :-
tf of;
C .‘
1 : T
I: ’.'
a: .00
5‘ '_ 3 3:
-r-'I 3:0
m - x a
I: f t‘.
G.) 'g.
«H z‘
I: "I if.
m - ‘1.
> f ,
'3 A P
CO
H
Q)
C!

 

 

l
ITTTIITTTITTTITTITIITTFIITrTTrj'
2195

TITTTTITrrrIITTrTl‘I

_1 2245
Wavenumber Shift (cm )

FIGURE 22

88

different information from the system. It was in this light that
density and viscosity measurements were made.

Since other researchers have had good success using a Stokes-
Einstein relation (as outlined in Chapter III) to compare rotational

44,48,49»53'76’77 this relation was

correlation times to viscosities,
applied to the reorientational correlation times obtained for SCB.
At this point there are two ways that the analysis could have been made.
One would have been to calculate the viscOsities from the experimental
correlation times and to match those to the experimental viscosities.
The other was to use the measured viscosities to calculate correlation
times and to match those to the times obtained from the lineshape
measurements. The second method was chosen since it was easy to obtain
viscosities over a wide temperature range.

The viscometer used measured the viscosity in units of centistokes,
so the density of SCB had to be obtained at the various temperatures
to convert to units of centipoise. The measured densities are
tabulated in Table l and compare favorably with those reported by Karat
and Madhusudana.29 After the unit conversion the measured viscosities

were fit to an Arrhenius type activation energy33’34

using a linear
least-squares routine.62 Both the experimental viscosities and those
calculated from the Arrhenius equation are given in Table 2. For

the isotropic phase (T 2 35°C) the calculated viscosity equation is:

n = (1.33 i 0.3) x 10-5 exp [(4340 : 120)/T] centipoise; (42)

89

TABLE 1

Density of 4-cyano-4'-pentylbiphenyl

T(°C) DCEm/ml) T(°C) D(8m/ml)
15.0 1.023 33.0 .9764
16.0 1.061 34.0 .9881
17.0 1.012 35.0 .9887
18.0 1.014 36.0 .9965
19.0 1.025 37.0 .9749
20.0 1.022 38.0 .9695
21.0- 1.012 39.0 .9798
22.0 1.018 40.0 .9927
23.0 1.018 41.0 .9991
24.0 . 984 42.0 .9730
25.0 1.037 43.0 .9672
26.0 1.024 44.0 .9556
27.0 1.061 45.0 .9410
28.0 1.044 46.0 .9085
29.0 1.054 47.0 .9096
30.0 1.017 48.0 .8950
31.0 1.030 49.0 .8843
32.0 1.021 50.0 .8563
TABLE 2

Experimental and Calculated Viscosities of 4-cyano-4'-pentylbiphenyl

T(°C) n(cp) calc.n(cp)
17.0 55.7 54.2 -
20.0 44.1 44.9
23.0 35.9 37.4
26.0 34.5 31-3
29.0 27.9 26.2
31.0 24.2 23.3
33.0 19.4 20.8
35.0 17.8 17.4
38.0 15.2 15.1
40.0 14.4 13.9
43.0 12.5 12.2
46.0 10.4 10-7
49.0 9.46 9-4

90

for the nematic liquid crystal phase (15°C 5 T 5 35°C) the equation is:
n = (6.11 i 3.0) x 10.7 exp [(5310 : 220)/T] centipoise. (43)

It seems reasonable that as the liquid becomes more ordered the
activation energy for Viscous flow would increase, since there would be
a greater hinderance to movement in an ordered system.

The reorientational correlation times were calculated using both
sticking and slipping boundary conditions. Equation 38 was used for
the sticking boundary condition. The unweighted equation is a
modification of Equations 33 and 35a and is the form:

3, = (V*n/kT)(1/3)(;e(oi)) + 2W(41/360)(1/kT)l/2o , (44)

i

The weighted slip equation is taken from Equations 33 and 35c and is:

12 = (V*n/kT)(ZWi9(pi)) + 2n(4l/360)(I/kT)1/2. (45)
1

The fourth equation used is a modification of Equation 37 which

incorporates the microviscosity factor and is:
1/2
T2 = (V*n/kT)(O.l63) + 2T(4l/360)(I/kT) . (46)

The calculated relaxtion times are summarized in Table 3 along with
calculated Viscosities and effective molecular volumes. The volumes
were calculated from the densities and are comparable to ones calculated

53°78 The calculated reorientational

for molecules of similar size.
correlation times from all four equations are longer than those obtained
from the Raman lineshape analysis. Those calculated with the microvis—

cosity factor (Equation 46) are the closest, but they are still one

e>wrm m
<wmnomwnwom. mmmmpnw<o ononcme <o~caom. man ”mymxmnwoa awamm mow Auoxmsoua.uuosnwacwwrmsww

91

aaonv :566wmmv <4moaug dammov ammonv Hammou dammnv
mnwnw cszowmrn tawmrn awnno<wmu
mew mpwv namwaw
xLONN xcoe xpoe xcoo xpoe
pm.o o.¢~m A.osm a.~¢ N.um m.A~ H.cN
Ho.o o.muu w.oom m.om N.HA A.mm o.o~a
Hu.o c.ma~ A.oo~ m.mA ~.Ho s.uo o.moo
Hm.o o.moo A.oma m.~m H.6u 5.5“ o.msm
no.0 c.5wm a.oao a.uo H.mN A.Ha o.umm
No.o o.sao A.om~ a.mo H.VH u.mo o.uuu
NH.o c.5Nm A.owu A.~u H.o~ w.ao o.ooo
~N.O o.umm a.oou u.©m H.mH m.a> o.om~
Nu.o o.uus E.Hnu u.mo H.Aa m.Nm o.o~u
NA.o o.um~ A.oam u.>m H.w~ u.o~ o.muH
Nm.o o.um~ m.cou u.- H.Nu N.qo o.m~o
No.o o.u~u A.osa m.ou H.Hu N.am o.mos
mu.o o.~mm w.©ou N.um ~.o¢ N.AH o.maw
Nm.c o.~um m.ooa ~.oa H.o~ ~.mo c.3uu
N©.c o.~aN u.©~© N.Aw o.c&o ~.HA c.5ou
uo.o o.~aq A.oww N.SH o.o~o ~.om o.mmo
w~.o o.~ww a.o~o N.NA c.mm~ H.wm o.mom
wN.o o.NNo a.omo N.~N o.mom H.ma o.wwo
uw.o o.~om A.NAH N.oo o.uoo H.mp o.wam
ms.o o._oq s.~o~ H.om o.qau H.om o.m-
mm.o o.~ua A.Hmm H.u~ o.mma H.Am o.~ma
mo.o o.~oo a.~mm H.o~ o.¢~u p.50 o.~om
uu.c o.~mw A.Nau H.mm o.oou H.uu o.~o~
um.o o.~m~ A.NuH H.mH o.mqa H.mo o.~ao
mo.o o.~sm A.N~¢ H.su o.mas H.Nm o.~uo
ao.o o.~mo A.~u~ ~.mm o.me H.Hm o.-m

92

a~.o
A~.o
Am.o
AA.o
am.o
ao.o
Au.o
Am.c
no.0
mo.o

o.~uu
o.-u
o.HNN
o.HHu
o.HHN
o.~ou
o.Hou

o.ocma
o.ooau
o.owom

a>wro u anosnwscmav

A.HAA
A.~mm
A.wa
A.wuw
n.5co
a.mmm
A.mm~
A.o~o
b.0mw
A.mua

H.Nm
H.Nm
H.No
H.H¢
H.Hw
H.HH
H.o<
H.om
c.00u
0.0mm

c.5mo
c.5uq
c.amm
o.AAA
o.awo
c.5NA
o.>ou
o.uca
c.wmw
c.muo

o.NHN
o.~o~
o.~mo
o.H©w
o.~mq
c.Hmm
c.~uu
o.HuN
o.~¢a
o.HoA

93

order of magnitude longer. It is interesting to note that the weighted
slip correlation times are closer to the sticking boundary condition than
the unweighted slip times are. This is just the opposite of what Fury
and Jonas observed,44 and indicates that sticking boundary conditions

may better describe SCB.

Since sticking boundary conditions may do a better job of
describing the reorientational behavior of systems comprised of long,
rod-like molecules such as 5CB, the question arises as to why the results
from Equation 38 are two orders of magnitude longer than those
calculated from the Raman lineshapes. The Stokes-Einstein relation
assumes that the molecules are in a fluid of continuous Viscosity.79
This Continuous medium assumption is not valid in a neat liquid and
therefore a correction should be made. Gierer and Wirtz8O postulated
a model involving concentric solvent shells, which for a neat liquid
reduces to Equation 37 and contains the microviscosity term. This
explains why Equation 46 does a better job in matching the Raman results.

It is still bothersome that the results of Equation 46 and the Raman
results differ by one order of magnitude. One possible explanation for
this discrepancy may be that the hydrodynamic models were developed
using spherical, or nearly spherical, molecules. Elongated liquid
crystal molecules are not spherical and will probably behave somewhat
differently when undergoing rotations. If this is the case, then one
might wonder about the validity of attempting to match the hydrodynamic
results to the lineshape results. Since other researchers were able to

obtain satisfactory results with the two methods,44"4°’48'°1’°:”’77’81

94

it was assumed that similar agreement could be obtained using SCB.
Since this is not the case it might be interesting to look into the

differences more at a later date.

VIII. CONCLUSIONS

In this work attempts were made to observe two different types of
relaxation processes involving anisotroPic media. One process was the
relaxation of a liquid crystal molecule in both the nematic and isotropic
phases. The other was the relaxation of a guest molecule surrounded
by molecules of a liquid crystal. Results for the first process, only,
could be Obtained. These results include both reorientational and
vibrational relaxation from Raman lineshapes. Reorientational correla-
tion times were also obtained for the liquid crystal system from
viscosity measurements.

The reorientational lifetimes obtained from Raman lineshapes
which are reported here can only be considered as approximate values,
due to the magnitude of the error associated with them. However, they
do indicate that more work must be done on the applicability of hydro-
dynamic theory for calculating correlation times in complex fluids,
since the correlation times calculated from viscosity data differ from
the Raman results by more than the combined experimental error. This
study does reinforce the vibrational relaxation work of other researchers,
which indicate that on a short time scale the total correlation function
is dominated by Vibrational relaxatio:n.‘°’7S

Since this research is just one piece in a large puzzle, it is
appropriate to suggest other experiments that could be performed, and
also experiments that should not be attempted. It would be very
interesting to obtain the rotational and possibly the vibrational

relaxation of a guest molecule in an anisotropic host, as was attempted

9S

96

here with acetonitrile in MBBA. In order for this type of experiment
to succeed one must keep the guest concentration low enough to insure
that the host still has an anisotropic phase. At such low concentra-
tions any host fluorescence becomes a problem that cannot be ignored.
The most obvious solution to this problem is to find a suitable host
that does not fluoresce, or to find a suitable quencher that can be
inserted into the host in very low concentrations. Since most liquid
crystal systems are aromatic, some fluorescence is likely in almost
every case. One way to reduce the fluorescence is to find a molecule

that has an electron withdrawing group, such as NO on the aromatic

. 82
ring.

2,

One could obviate the fluorescence background problem by preforming
Coherent Anti-Stokes Raman Scattering (CARS) experiments. Since anti-
Stokes scattering is monitored, fluorescence would be minimized.83
Another method would be to use a pulsed laser source and gated detection
electronics. This experimental setup is useful since the lifetime of
the Raman scattering is shorter than the risetime of the fluorescence
signal.

As was mentioned earlier, there are a number of pitfalls associated
with extracting the reorientational function from a Raman band. One
problem arises from truncation error when Lorentzian functions are
deconvulated by Fourier transformation.84 This problem could possibly
be overcome by using the solution of a Fredholm integral equation Of the

first kind,85’86

in which a finite time range of the data is exactly
accounted for. With this approach it might be possible to obtain
differences in the correlation functions arising from both vibrations and

rotations at longer times.

97

Another problem is caused by overlapping bands, and this is
particularly severe when the bands have different polarization
characteristics. Any attempt to mathematically separate overlapping
bands will change the overall shape of each individual band, and this
effect will more than likely be different for depolarized scattering
than for polarized scattering. This is the main reason why care should
be taken when choosing a Raman band for analysis.

Weak bands pose another problem. In order to obtain reliable
lineshapes, the relative signal-to-noise ratio must be high; that is,
the noise level must be many times smaller than the difference between
the baseline and the peak maximum. Some ways of experimently dealing
with this problem have been outlined by Griffiths.87 As a last resort,
weak bands with a low S/N can be digitally smoothed. However, this

64

technique may also change the overall shape of a Raman band and thus

could change the final results unless an appropriate correction is used.

APPENDICES

APPENDIX A

PROGRAM DATCOL

A FORTRAN/SABR program that controls a Jarrell-Ash Raman spectro-

meter and collects counts from the photomultiplier tube.

98

99

PROGRAM DATCOL. FT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC’

OOOOOODOOOOOQOOOODOOOOOOO000000GOOD0000OOOOOOOOOOOOOODOOOOOOOOOOOOOO

PROGRAM DATCOL
RAMAN DATA TAKING PROGRAM

PROGRAM WILL CONTROL THE JARRELL-ASH RAMAN SPECTROMETER ‘AS
WELL AS COLLECT THE COUNTS COMING FROM THE PMI'.

IT WILL TAKE UP TO 100 SCANS OVER A REGION OF INTEREST.
WHEN THE ENDING FREQUENCY IS REACHED. THE GRATING WILL

BE PUT BACK AT THE STARTING FREQUENCY.

BACKLASH IN THE GEARS IS TAKEN CARE OF BY GOING 50 CM-l BY
THE STARTING FREQUENCY AND COMING BACK TO IT.

THIS WILL NOT AUTOMATICALLY HAPPEN IF THE STARTING FREQUENCY
IS LESS THAN 70 CM-l.

THE COUNT TIME CAN BE VARIED FROM 100 PEEC TO 40 SEC.

EACH DATA FILE IS ENDED WITH A NEGATIVE NUMBER.

THE PROGRAM CAN BE INTERRUPTED BY A CONTROL G. THE OPERATOR
THEN HAS THE OPTION OF CONTINUING. CLOSING THE FILE AND
STOPPING. OR. STOPPING WITHOUT CLOSING THE FILE.

IF THE PROGRAM IS CONTINUED. THE OPERATOR HAS THE OPTION

OF CHANGING SOME OF THE PARAMETERS.

WHEN THE RUN IS OVER. THE OPERATOR HAS THE OPTION-TO
RESTART. MOVE THE GRATING. 0R CRUNCH DATA.

COMMON VARIABLES USED IN THIS PROGRAM

SN MAXIMUM NUMBER OF COUNTS DESIRED

XNU CURRENT FREQUENCY INSTURMENT IS AT

YCNT‘ COUNTS/SEC AT XNU

[STEP NUMBER OF STEPS STEPPING PDTDR WILL TAKE
BETWEEN DATA POINTS

TIME MAXIMUM COUNT TIME

TMIN MINIMUM COUNT TIME

SNU STARTING FREQUENCY

FNU ENDING FREQUENCY

NSTEP NUMBER OF STEPS RECORDER WILL TAKE
BETWEEN DATA POINTS

INTERNAL VARIABLES

DEV OUTPUT STORAGE DEVICE

FILE OUTPUT STORAGE FILE NAME

RESOL DESIRED FREQUENCY INTERVAL BETWEEN
DATA POINTS

YMAX MAXIMUM COUNT/SEC RANGE FOR PLOT

IY INTEGER Y COORDINATE FOR PLOT

NTIMES NUMBER OF SCANS OVER REGION

ITEMP TEMPORARY [STEP STORAGE

AY TEMPORARY STORAGE FOR PLOT PARAMETER
IMO MONTH

IDAY DAY

IYR YEAR

XDONE LAST X VALUE

YDONE LAST Y VALUE

STEP CM-l/INCH RECORDER WILL MOVE
IVAL CHARACTER STORAGE

IC FLAG FOR CONTROL C

IG FLAG FOR CONTROL G

SUBROUTI NES USED

OOPEN( DEV. F ILE)
SCST( I)

SAMPLE

SCAN ( J)

SCPLT( NSTEP . I)
OCLOSE

BELL

100

DATCOL. CONT.

C SCEND

C EXPP

C LIMJT(IL.RVAR.IH)

C ERASE

C YESNO(IVAL)

CHAIN

KEHEK(IDUM)
FILE(DEV.FIL.IMDDE)
CHANGE
LETIN(IVAL.IC.IG)

STEPHEN M. GREGORY
APRIL 17. 1978

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
COMMON SN.XNU.YCNT.ISTEP.TIME.TMIN.NSTEP.SNU.FNU.YMAX
DIMENSION DEV(100).FNAME(100)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC‘
C
C GET DATE WORD
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

S DUMMY DATE

S TAD I DATE

8 DCA TEMP

S TAD TEMP

S AND (7

S DCA iYR

S TAD TEMP

S RAR

S RTR

S AND (37

S DCA {DAY

S TAD TEMP

S CLL RAL

S RTL

S RTL

S AND (17

S DCA 1M0
GO TO 1

S CPAGE 3

S DATE. 6211

S 7666

S TEMP. 0

1 IF(IMD)2.2.3

2 WRITE(1.100)
GO TO 29

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC'

C

C SET UP INITIAL VALUES

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

3 CALL BELL
IYRFIYRfia

WRITE(1.101) IMD.IDAY.IYR.
WRITE (1.102)
READ (1.103) TIME.TMIN
READ (1.104) SNU.FNU
READ (1.105) SN
READ (1.106) RESOL
READ (1.107) NTIMES
READ(1.108) STEP
READ(1.109) YMAX
XNU=SNU
ISTEP=IFIXIRESOL¥20.)
STEP=300.*RESOL/STEP
NSTEP‘LIMIT(1.STEP.2047)
DO 5 I=1.NTIMES

4 IMODE=0

101

DATCOL. CONT.

WRITE(1.110) I
CALL FILE( DEV( I) .FNAPE( I) . IMDE)
IMODE=IMODE+3
GO TO (3.29.4.5) IMODE
5 CONTINUE
CALL ERASE
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C COLLECT DATA
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
DO 20 I81.NTIMES
CALL OOPEN(DEV(I).FNAME(I))
CALL SCST(0)
IF(XNU-FNU)7.7.15
CALL SAMPLE
CALL SCAN(1)
AYiYCNT*2047./YMAX
IY‘LIMITCO.AY.2047)
CALL SCPLT(NSTEP.IY)
CALL KCHEK(IDUM)
IF(IDUM)14.14,8
8 WRITE(1.111) XNUQYCNT
CALL YESNO(IVAL)
IF(IVAL-89)11.9.11
9 WRITE(1.112)
CALL YESNO(IVAL)
IF(IVAL-89)14.10.14
10 CALL CHANGE
GO TO 14
11 WRITE(1.113)
CALL YESNO(IVAL)
IF(IVAL-89)13.12.13
12 WRITE(4.114) XNU.YCNT
XNU=XNU+RESOL
GO TO 15
13 XNU=XNU¥RESOL
CALL SCEND
GO TO 16
14 WRITE (4.114) XNU.YCNT
XNU=XNU+RESOL ‘
GO TO 6
l5 XDONE3-1000.
YDONE=0.
WRITE(4.114) XDONE.YDONE
CALL OCLOSE
CALL SCEND
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCECCCCCCC
C

C MOVE GRATING BACK TO STARTING POINT

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
16 XNU=XNUPRESOL
CALL SCAN(2)
17 ITEMP=ISTEP
IF(SNU-70.)18,18.19
18 CALL BELL
READ( 1.115) IBLOCK
19 ISTEP=1000
CALL SCAN(2)
CALL SCAN(1)
ISTEP=ITEMP
20 CONTINUE
CALL BELL
WRITE(1.116)
CALL YESNO(IVAL)
IF(IVAL-89)21.29.21
21 WRITE(1.117)

«no

102

DATCOL . CONT .

22
23
24
25
26

27
28
29

CALL LETTN(IVAL.IC.IG)
IF(IC-1)22.29.22
IF(IG—1)23.21.23
IF(IVAL-210)24.26.24
IF(IVAL-847)25.27.25
IF(IVAL-257)21.28.21
CALL ERASE

CALL CHAIN(’CRDNCR’)
CALL ERASE

CALL CHAIN(’MOVE’)
CALL ERASE

GO TO 3

CALL EXIT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C
C

FORMAT STATEMENTS

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

100
101
102
103

104
105
106
107
108
109
110
1.1 1

112
113
114
115
116
117

FORMAT( ’ ENTER CURRENT DATE AND RESTART PROGRAM’)
FORMAT(’ DATE IS ’.2X. I2.’/’.I2.’/197’.I1)

FORMAT( ’ RAMAN DATA TAKING PROGRAM’)

FORMAT( ’ MAX COUNT TII‘E IN SEC = ’.F10.4/’ MIN COUNT TIME
1 IN SEC 3 ’.Fl0.4)

FORMAT( ’ STARTING POINT 3 ’.F10.4/’ ENDING POINT 8 '.F10.4)
FORMAT(’ DESIRED NUMBER. OF COUNTS 3 ’.F10.4)

FORMAT( ’ SPACING BETWEEN DATA POINTS 3 ’ .F10.4)

FORMAT( ’ HOW MANY SCANS ? ’ .13)

FORMAT1’ CM-I/INCH 0N RECORDER ‘-' ’ .F10.4)

FORMAT( ’ MAXIMUM COUNT/SEC ON RECORDER = ’ .F10.4)
FORMAT( ’ OUTPUT FILE ’ . 12)

FORMAT( ’ CURRENT FREQUENCY IS ’ .F10.4/’ CURRENT COUNTS/SEC
1 ARE ’.E10.4/’ DO YOU WANT TO CONTINUE 9’)

FORMAT( ’ DO YOU WANT TO CHANGE ANY OF THE PARAI‘ETERS ?’)
FORMAT( ’ DO YOU WANT TO SAVE THE COLLECTED DATA ?’)
FORMAT(2A6)

FORMAT( ’ BLOCK THE SLITS AND HIT RETURN’ . I1)

FORMAT( ’ DONE ?’)

FORMAT( ’ CRUNCH. MOVE. OR DATCOL 7’)

END

SUBROUTINE SAMPLE. FT

SUBROUTINE SAMPLE

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

OODDOOOOOOOOOOOOOOOOO

SUBROUTINE TO COUNT PHOTONS
INITIAL COUNT PERIOD IS 100 PEEC AND IT WILL COUNT UP TO 40 SEC

COMMON VARIABLES USED
YCNT COUNTS/SEC.
SN SIGNAL/NOISE
TII‘E COUNT TIME
TMIN MINIMUM COUNT TIME

I NTERNAL VARI ABLES

IXH H I GB OVERFLOW STORAGE

I YL LOW ORDER COUNT STORAGE

I YH HIGH ORDER COUNT STORAGE
AYL FLOATI N G I YL

AYH FLOAT I N G I YH

AXH FLOAT! NC I XH

YC TEMP COUNTS/SEC

TMAX MAXIMUM COUNTING TII‘E

SAMPLE .

UHDDODOO mmmmmmmmmmmmmmonnnoo

mmmmwm

ODOOOOOOGOODOOOOOOOOOOOOO

CONT.

2532

103

INTEGER COUNT TIDE

STORAGE FOR DEB OF LOW COUNT
STORAGE FOR DEB OF HIGH COUNT
STORAGE FOR DSB OF OVERFLOW WORD

SUBROUTINES CALLED

DFIX (RVAR. IH. IL)
DFLOT ( IH. IL. RVAR.)

OPERATIONS DEF INED

LPSET LOAD PRESET REGISTER

STPGM START PROGRAM CLOCK

LCTRL LOAD CONTROL REGISTER

POSKP PGM OFLOW SKIP

CLRCT CLEAR RAMAN COUNTER

COUNT START PHOTON COUNTING

STPCT STOP COUNTING

LTCTR LATCH COUNTER INTO COMPUTER

CLRLO CLEAR LOW OVERFLOW

CBKHO CHECK HIGH OVERFLOW

CLRHO CLEAR HIGH OVERFLOW

SDIPLL SAMPLE LOW COUNT

SMPLH SAMPLE HIGH COUNT

DRIVE DRIVE INTO AC
STEPHEN M. GREGORY
APRIL 12. 1978

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

OPDEF LPSET 6121 /LOAD PRESET REGISTER
OPDEF STPGM 6 123 /START PROGRAM CLOCK
OPDEF LCTRL 6 131 /LOAD CONTROL REGISTER
SKPDF POSIG’ 6132 /PGM OFLOW SKIP
OPDEF CLRCT 6601 /CLEAR RAMAN COUNTER
OPDEF COUNT 6602 /START PHOTON COUNTING
OPDEF STPCT 6608 /S'IOP COUNTING
OPDEF LTCTR 6604 /LATCH COUNTER INTO COMPUTER
OPDEF CLRLO 6606 /CLEAR LOW OVERFLOW
SKPDF CHKHO 6607 /CHECK HIGH OVERFLOW
OPDEF CLRHO 6611 /CLEAR HIGH OVERFLOW
OPDEF SMPLL 6612 /SAMPLE LOW COUNT
OPDEF SMPLH 6613 /SAMPLE HIGH COUNT
OPDEF DRIVE 6617 /DRIVE INTO AC

COMMON SN. XNU. YCNT. ISTEP. TIDIE.TMIN. NSTEP.SNU. FNU.YMAX

INITIALIZE

IXH=0
NYH=0
NYL=0
IYL=0
IYH=0
NXR=0

TMIN=TMIN=IK 100 .

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
CLRCT
CLA CLL

CALL DFIX( TMIN. IH. IMIN)
CALL DFLOT( IH. IMIN.TMIN)

TMIN=TMIN/ 100.
CLA CLL

TAD

LCTRL
CLRLO
CLRHO

CLACLL

( 4404

1 04
SAMPLE. CONT.

S TAD IMIN
S C I A
S LPSET
S CLA CLL
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C COUNT FOR TMIN SEC
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
S STPGM
S COUNT
S B. CHKHO / CHECK HIGH, OVERFLOW
S J D? ‘ C
S JD? D
S C . POSKP / CHECK CLOCK OVERFLOW
S JD? B
S STPCT /STOP COUNTING
S CHKHO
S J D? F
S I 52 1 KB
S NOP
S CLRHO
S F . CLA CLL
S LTCTR
S 8MPLL
S NOP
S DRI VE.
S DCA 1 YL
S SD?LH
S NOP
S DRIVE
S DCA IYR
S JD? E
S D . I 82 i XH
S NOP
S CLRHO
S JD? C
S E . NOP
III3 0

CALL DFLOT( IYR. IYL.AY)

CALL DFLOT( IH. IXH. AXH)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCGCCCCCCCC
C

C CALCULATE COUNT/SEC

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
YCNTa AY+AXH*8192 .

IF(YCNT-SN) 1. 12. 12
YC=YCNT/TMIN
IF(YCNT)2. 12.2
TMAX=ABS(SN/YC)
IF(TMAX-TMIN)3.4.4
TMAX=TMIN

IF( TMAX-TIDE)5.5. l2
TI=TIDIE*100.
IF(TI-4096. )?.7.6
T134096.
TM=TMAX=K100.
IF(TM'40960)9’998
TM=4096.
IF(TM-TI)11. ll. 10
TM=TI

CALL DFIX( TM. IH. ITO)
IH=0

CALL DFLOT( IH. I.TC.TM)
TMAX=TDV 100. '
CLRCT

CLRHO

CLRLO

A—om do now N H
HO

mmm

105
smut. com.

CLA CLL
TAD iTC
CIA

LPSET

CLA CLL
IXB?0

NYL=0

NYH=O

IYL=0

IYH*O

NXB=0

S CLA CLL
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC.
C

mmmmm

C START COUNTING

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

S STPGM

S COUNT

S BB. ClflflD

S JMP CC

S JMP DD

S CC. POSEP

S JMP BB

S STPCT

S CHKHO

S JMP FF

S 182 1X3

S NOP

S CLRHO

S FF. CLA CLL

S LTCTR

S SHPLL

S NOP

S DRIVE

S DCA iYL

S SMPLH

S NOP

S DRIVE

S DCA iYH

S JMP EE

S DD. 182 1X3

S NOP

S CLRHO

S JMP CC

S EE. NOP
1330

CALL DFLOT(IYH.IYL.AY)

CALL DFLOT(IH.IXH.AXE)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC'
C

C CALCULATE COUNTVSEC
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
YCNT’AY¥AXH*8192.
GO TO 13
12 YCNT=YCNT7TMIN
GO TO 14

13 YCNT=YCNTVTMAX
14 RETURN
END

106

SUBBOUTINE SCAN.FT

SUBROUTINE SCAN(IWAY)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

SUBROUTINE TO DRIVE STEPPING MOTOR
COMMON VARIABLES USED

ISTEP NUMBER OF STEPS
INTERNAL VARIABLES

IWAY 1 FOR FORHARD
2 FOR.REVERSE

SUBROUTINES CALLED
NONE
OPERATIONS DEFINED

REVS MOVE GRATING IN REVERSE DIRECTION
PORNO MOVE GRATING FORWARD
STEP STEP THE STEPPING MOTOR.ONCE

STEPHEN M. GREGORY
APRIL 12. 1978

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
S OPDEF REVS 6614 /REVERSE

OPDEF FORWD 6615 /FORNARD

OPDEF STEP 6616 /STEP DRIVE MOTOR

COMMON SN,XNU,YCNT.ISTEP.TIME.TMIN.NSTEP,SNU,FNU.YMAX
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C MOVES TEE GRATING A DISTANCE OF RESOL

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCG

DO 4 I81,ISTEP

GO TO (1,2)IWAY

CONTINUE

FORHD

GO TO 3

CONTINUE

REVS

CONTINUE

STEP
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC.

A WAIT LOOP TO LET EVERYTHING SETTLE DOWN.
STEPPING MOTOR CANNOT STEP FASTER.TRAN 441.50L

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
CLA CLL
TAD (2000
CIA
A. IAC '
SZA
JMP A
NOP
CONTINUE
RETURN
END

C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
S
S
C

JMDCOWQUJQIDOOOOOOIDCOWN wv‘

107

SURROUTINE CRANGE.FT

SUBROUTINE CHANGE
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

SUBROUTINE TO CHANGE PARAMETERS DURING A RAMAN DATA RUN.
COMMON VARIABLES USED

SN MAXIMUM NUMBER.OF COUNTS DESIRED

ISTEP NUMBER OF STEPS STEPPING MOTOR.WILL TAKE
BETWEEN DATA POINTS

TIME MAXIMUM COUNT TIME

TMIN MINIMUM COUNT TIME

NSTEP NUMBER OF STEPS RECORDER WILL TAKE BETWEEN

DATA POINTS
SNU STARTING FREQUENCY
FNU ENDING FREQUENCY

YMAX MAXIMUM COUNTS/SEC ON RECORDER
INTERNAL VARIABLES

RESOL DESIRED FREQUENCY INTERVAL BETWEEN DATA
POINTS

STEP CMFl/INCH RECORDER.WILL MOVE

IVAL CHARACTER.STORAGE

00000000000000000000000

SUBROUTINES USED

ERASE
YESNO(IVAL)
LIMJT(IL.RVAR.IH)

STEPHEN M. GREGORY
APRIL 12. 1978

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
COMMON SN,XNU.YCNT,ISTEP.TIME.TMIN.NSTEP.SNU,FNU.YMAX
CALL ERASE
gCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

0000000000

C MAXIMUM COUNT TIME

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
WRITE(1.IOO)
CALL YESNO(IVAL)
IF(IVAL-89)2.l.2
1 READ(1.101) TIME
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C MINIMUM COUNT TIME

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
2 WRITE(1.102)

CALL YESNO(IVAL)

IF(IVAL-89)4.3.4
3 READ(1.101) TMIN
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C STARTING FREQUENCY

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
4 WRITE(1,103)

CALL YESNO(IVAL)

IF(IVAL-89)6,5,6
3 READ(1.101) SNU
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C ENDING FREQUENCY
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

108

CHANGE. CONT.

6 WRITE(1.104)

CALL YESNO(IVAL)

IF(IVAL-B9)8.7,8
7 READ(1.101) FNU
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C TOTAL NUMBER.OF COUNTS

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
8 WRITE(1.105)

CALL YESNO(IVAL)

IF(IVAL-89)10.9.10
9 READ(1.101) SN
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC‘
C

C SPACING BETWEEN DATA POINTS
C \
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
IO WRITE(I.IOG)

CALL YESNO(IVAL)

IF(IVAL-89)I2.II,12
II READ(I.IOI) RESOL

ISTEP=IFIX(RESOL*20.)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C CH‘l/INCH ON RECORDER
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
12 WRITE(I.IO7)

CALL YESNOCIVAL)

IF(IVAL-89)l4.l3.l4
I3 READ(I.IOI) STEP

STEP=SOO.*RESOL/STEP

NSTEP=LIMIT(I.STEP.2047)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C MAXIMUM.COUNTS/SEC ON RECORDER

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
14 WRITE(1.108)

CALL YESNO(IVAL)

IF(IVAL-89)16.l5,16
15 READ(1.101) YMAX
16 CALL ERASE

RETURN
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C FORMAT STATEMENTS

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

100 FORMAT(’ MAXIMUM COUNT TIME ?’)

101 FORMAT(’? ',F10.4)

102 FORMAT(’ MINIMUM COUNT TIME ?’)

103 FORMAT(' STARTING FREQUENCY ?')

104 FORMAT(’ ENDING FREQUENCY 7’)

105 FORMAT(' TOTAL NUMBER OF COUNTS ?’)

106 FORMAT(’ SPACING BETWEEN DATA POINTS ?')

107 FORMAT(’ CMFI/INCH ON RECORDER ?’)

108 FORMAT(’ MAXIMUM COUNTS/SEC ON RECORDER ?’)
END

APPENDIX B

PROGRAM MOVE

A FORTRAN/SABR program to move the grating of a Jarrell-Ash
Raman spectrometer. It will also calibrate the system with respect

to the excitation frequency.

109

110

PROGRAM MOVE.FT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

0000000000000000000000

000000000000000000000000

PROGRAM MOVE

THIS PROGRAM WILL MOVE THE GRATING OF THE RAMAN SPECTROMETER
TO A NEW FREQUENCY. IF THE STARTING FREQUENCY HAS NOT BEEN
DETERMINED. THEN THIS PROGRAM WILL RUN OVER THE EXCITING LINE
AND SET THE GRATING THE DESIRED DISTANCE AWAY.

MONOCHROMETER MUST BE SET UP SO THAT IT IS 5 CM-l ABOVE THE
EXCITING FREQUENCY WHEN CALIBRATING.

COMMON VARIABLES USED

SN MAXIMUM NUMBER OF COUNTS DESIRED

XNU CURRENT FREQUENCY INSTRUMENT IS AT

YCNT COUNTS/SEC AT XNU

ISTEP NUMBER OF STEPS STEPPING MOTOR WILL TAKE
BETWEEN DATA POINTS

TIME MAXIMUM COUNT TIME

STEP CMFl/INCH RECORDER WILL MOVE

TMIN MINIMUM COUNT TIME

INTERNAL VARIABLES

Y ARRAY FOR COUNT/SEC STORAGE
ITOP INDEX FOR MAXIMUM IN Y ARRAY
XSET FREQUENCY TO BE SET
DIST DISTANCE TO BE MOVED
IMO MONTH
IDAY DAY
IYR YEAR
SUBROUTINES USED
SAMPLE
SCAN(J)
BELL
ERASE
LETIN(IVAL,IC.IG)
YESNO(IVAL)
CHAIN
KOHEK(IDUM)

STEPHEN M. GREGORY
APRIL 17. 1978

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

COMMON SN,XNU,YCNT,ISTEP.TIME.TMIN.NSTEP,SNU.FNU.YMAX
DIMENSION Y(200)

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

C
C
C

GET DATE WORD

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

UJUJUIUJUJUJUJUJUJUIUJWWUJ

WRITE(I,100)
DUMMY DATE
TAD I DATE

DCA TEMP
TAD TEMP
AND (7
DCA IYR
TAD TEMP
RAR

RTE

AND (37
DCA iDAY
TAD TEMP
CLL RAL

RTL

111

MOVE. CONT.

S RTL

S AND (17

S DCA iMO
GO TO 1

S CPAGE 3

8 DATE. 6211

S 7666

S TEMP. 0

1 IF(IMO)2,2,4

2 CALL BELL
WRITE(1.101)

3 STOP

4 CALL BELL
IYR=IYR+8

WRITE(1.102) IMO.IDAY.IYR
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C BRANCH TO DESIRED ROUTINE

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
5 WRITE(1.103)

CALL LETIN(IVAL.IC.IG)

IF(IC‘I)6,3.6

IF(IC-I)7.5.7

IF(IVAL-I93)5.29,5
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

m'das

SET DISTANCE TO BE MOVED .
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
READ(1.104) XNU
READ(1 . 105) XSET
CALL ERASE
DIST=XSET-XNU
IF(DIST)11.22.12
11 J=2

DIRF-l.

GO TO 13
12 J=1

DIR=1.
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

~000000

O

C MOVE GRATING
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
13 DMOVE=.05*DIR

ISTEP=1
14 CALL SCAN(J)

CALL KCHEK(IDUM)

IF(IDUM)15,15.17

15 IF(ABS(DMOVE)-ABS(DIST))16.18.18
16 DMOVE=DMOVE+.05*DIR
GO TO 14

17 XD=XNU+DMOVE

WRITE(1,106) XD

CALL YESNO(IVAL)

IF(IVAL-89)22.15,22
18 IF(DIR)19.22.22
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C MOVE GRATING TO RELEAVE BACKLASH

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
19 IF(XSET—70.)20.20,21

20 READ(1,107)IBLOCK

21 ISTEP=1000

CALL SCAN(2)
CALL SCAN(1)

112
MOVE. CONT.
22 WRITE(1. 108)

CALL LETIN(IVAL,IC,IG)
IF(IC-1)23.3.23

23 IF(IG-1)24.22,24

24 IF(IVAL-210)25.27,25
25 IF(IVAL-847)26.5.26
26 IF(IVAL-257)22.28.22

27 CALL ERASE

CALL CHAIN(’CRUNCH’)
28 CALL ERASE

CALL CHAIN(‘DATCOL')
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C RUN OVER EXCITING LINE
C .
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
29 CALL ERASE
ISTEPSI
SN=10000.
TIME=5.
TMIN=.1
DO 30 I=1.200
CALL SAMPLE
Y( I)=YCNT
30 CALL SCAN(1)
YMAX=Y(1)
DO 32 I=2.200
IF(Y(I)-YMAX)32.31.31
31 YMAX=Y(I)
ITOP=I
32 CONTINUE
XNU=FLOAT(200-ITOP)*.05

CALL BELL

GO TO 10
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC.
C
C FORMAT STATEMENTS

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

100 FORMAT(‘ PROGRAM TO MOVE THE GRATING')

101 FORMAT(’ ENTER CURRENT DATE AND RESTART PROGRAM’)

102 FORMAT(’ DATE IS ’.12.’/',12.’/197’.I1)

103 FORMAT(’ DO YOU WANT TO MOVE OR CALIBRATE ?‘)

104 FORMAT(’ WHAT FREQUENCY ARE YOU AT NOW ? ’.F10.4)

105 FORMAT(’ WHAT FREQUENCY DO YOU WANT ? ',Fl0.4)

106 FORMAT(' CURRENT FREQUENCY IS ’.F10.4/’ DO YOU WANT TO
1 CONTINUE ?’)

107 FORMAT(’ HIT RETURN AFTER BLOCKING LASER.BEAM',II)

108 FORMAT(‘ CRUNCH. MOVE. 0R DATCOL ?’)
END

APPENDIX C

PROGRAM CRUNCH

A FORTRAN/SABR program that will help in the analysis of Raman
spectra. The features include plotting, smoothing of spectra,
baseline substraction, normalization of peaks, scale expansion on plots,

signal averaging, background subtraction, and peak location.

114

PROGRAM CRUNCH. FT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC’

00000000000000000000000000000000000000000000000000000000000000000000

PROGRAM CRUNCH
PROGRAM TO CRUNCH RAMAN DATA

STEPHEN M. GREGORY
APRIL 17. 1978

THIS IS THE TRAFFIC DIRECTOR FOR A SET OF PROGRAMS DESIGNED
TO DISPLAY AND ANALYZE RAMAN DATA

OPTIONS ARE CHOSEN BY TYPING IN THE NAME OF THE.OPTION
DESIRED. WHEN A QUESTION IS ASKED THAT REQUIRES A YES OR
NO ANSWER. RESPOND WITH A YVN DEPENDING ON YOUR ANSWER.
OPTIONS THAT THE PROGRAM HAS ARE PLOTTING. SMOOTHING.
CORRECTING FOR A LINEAR BASELINE DRIFT, NORMALIZATION

OF SINGLE PEAKS. SCALE EXPANSION OF PLOTS. PRINTING.
TRANSLATING TO E FORMAT, AVERAGEING 0F MANY SPECTRA.

OR PEAK SUBTRACTION.

INITIAL DIALOGUE IS NOT NEEDED FOR TRANSLATING.

VARIABLES USED IN THIS PROGRAM AND SUBROUTINES

COMMON XMIN MINIMUM FREQUENCY FOR THIS RUN
XMAX MAXIMUM FREQUENCY FOR RUN
YMIN MINIMUM VALUE OF Y IN RANGE
YMAX MAXIMUM VALUE OF Y IN RANGE
DELX. FREQUENCY INTERVAL BETWEEN DATA POINTS
ITYPE 3 FOR PLOT
FOR SMOOTHING
FOR BASELINE CORRECTION
FOR NORMALIZATION
FOR SCALE EXPANSION
FOR SIGNAL AVERAGEING
FOR PRINTING
FOR TRANSLATION
FOR PEAK LOCATION
DEVI DEVICE INPUT DATA IS STORED ON
DEV2 DEVICE OUTPUT DATA IS TO BE STORED ON
FILEI INPUT FILE NAME
FILE2 OUTPUT FILE NAME
IPLOT = 1 FOR.STRIP CHART RECORDER
2 FOR TERMINAL
IDONE FLAG RAISED WHEN PROGRAM IS FINISHED
X LAST FREQUENCY VALUE READ FROM INPUT FILE
Y LAST COUNT VALUE READ FROMIINPUT FILE
IPST 1 IF PLOT HAS STARTED
ALSO INDEX FOR PEAKS
IBASE 1 FOR CALCULATION OF SUMS
2 IF ALL POINTS HAVE BEEN READ IN FOR.BASELINE
CALCULATION
3 IF SLOPE AND INTERCEPT HAVE BEEN CALCULATED
INORM 1 IF SCALE HAS BEEN DETERMINED
NTST 0 UPON ENTERING NORM
1 WHEN YMAX HAS BEEN READ IN
-1 WHEN SCALING HAS STARTED
ISIG = 1 FOR ADDITION
2 FOR SUBTRACTION

Oflfld‘fléGNt-e

INTERNAL VARIABLES
IVAL USED FOR CHARACTER STORAGE

IC USED AS A FLAG FOR CONTROL C
IG USED AS A FLAG FOR CONTROL G
IMO MONTH

IDAY DAY

IYR YEAR

IMODE I/O MODE AND RETURN FLAG

CRUNCH.

O

OOOOGOOOOOOOOOODOOOOO

CONTfi

115

SUBROUTTNES CALLED

BELL

YESNO(IVAL)
LETIN(IVAL.IC.IG)

RDAT

ERASE

FILE(DEV.FIL.IMODE)

OUTPUT'IS INTENDED TO THE
DEV AND FIL ENTERED
INPUT'IS INTENDED FROM THE
DEV AND FIL ENTERED

G ENCOUNTERED

C ENCOUNTERED

SYNTAX ERROR OR INAPPROPRIATE
DEVICE

EVERYTHING IS OKAY.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

COMMON XMIN.XMAX.YMIN.YMAX»DELX.ITYPE.DEVI,DEV2.FILE1.FILE2.

IPLOT.IDONE.X;Y.IPST.IBASE.INORM.NTST.ISIG

1
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCGCC

C
C
C

m—mmmm wwmmmmmmmwmmmmmmm

GET DATE WORD
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
DUMMY

DATE
TAD I DATE
DCA TEMP
TAD TEMP
AND (7
DCA lYR
TAD TEMP
RAR
RTR
AND (37
DCA {DAY
TAD TEMP
CLL RAL
RTL
RTL
AND (17
DCA iMO
GO TO 1
CPAGE 3
DATE. 6211
7666
TEMP. O

IF(IMO)2.2.3
CALL BELL
WRITE(1,IOO)

GO TO 49

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

GET FILE NAMES AND INITIAL VALUES
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

CALL BELL
IYRfiIYRka

C
C

3

IDONE=0

WRITE(1,101) IMO,IDAY.IYR.
WRITE( l , 102)

CALL YESNO(IVAL)

IF(IVAL-89)8,4,8

YMAX30
YMIN=O

116
CRUNCH. CONT.

5 IMODE=1
WRITE(1.103)
CALL FILE(DEV1,FILEI,IMODE)
IMODE=IMODE+3
GO TO (3.49.5.6) IMODE
6 IMODE=
WRITE(1,IO4)
CALL F ILE( DEV2 . F ILE2 . IMODE)

IMODE=IMODE+3

GO TO (3.49.6.7) IMODE
7 READ(1.103) XMIN.XMAX.DELX
8 WRITE(1.106)

CALL LETIN(IVAL.IC.IG)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C SET UP ITYPE FOR BRANCHING

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
IF(IC-1)9.49,9

9 IF(IG-1)10.3.10

10 IF(IVAL-IO36)11.22.11
11 IF(IVAL-l229)l2.23.l2
12 IF(IVAL-l29)13.24.13

13 IF(IVAL-911)14.25.14

14 IF(IVAL-344)15.26.15

15 IF(IVAL-1042)16.21.16
16 IF(IVAL-l298)l7.20.17

17 IF(IVAL-1225)18.27.18
18 IF(IVAL-1029)8.l9.8
19 FTYPE=9

GO TO 40
2O ITYPE=8
GO TO 40
21 ITYPES?
GO TO 40
22 ITYPE=1
GO TO 34
23 ITYPE=2
GO TO 40
24 ITYPE=3
GO TO 40
25 ITYPE=4
GO TO 40
26 ITYPE=5
GO TO 40
27 ITYPE=6

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C SET UP ISIG
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
28 WRITE(1.107)

CALL LETIN(IVAL.IC.IG)

IF(IC-l)29.49,29

30 IF(IVAL-68)31.32.31
31 IF(IVAL-1237)28.33.28
32 ISIG=1
GO TO 40
33 ISIG=2
GO TO 40
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C SET UP IPLOT
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
34 WRITE(1.108)

CALL LETIN(IVAL.IC.IG)

IF(IC-1)35,49,35

117

CRUNCH. CONT.

35
36
37
38

39
40
41

42
43
44
45
46

47
48
49

IF(IG-l)36.3,36
IF(IVAL-1236)37.38.37
IF(IVAL-1285)34.39,34
IPLOT?!

GO TO 40

IPLOT=2

CALL ERASE

CALL RDAT
IF(IDONE)4I.4I.49
WRITE(I.109)

CALL LETIN(IVAL.IC.IG)
IF(IC-1)42.49.42
IF(IG-l)43.4l,43
IF(IVAL-210)44.48.44
IF(IVAL-847)45,46,45
CALL ERASE

CALL CHAIN(’MOVE')
CALL ERASE

CALL CHAIN(’DATCOL’)
CALL ERASE

GO TO 3

STOP

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C
C

FORMAT STATEMENTS

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

100
101
102

103
104
105

106

107
108
109

FORMAT( ’ENTER CURRENT DATE AND RESTART PROGRAM’)

FORMAT(’ DATE IS ’.2X.I2.’/’.I2.'/197'.I1)

FORMATI’ PROGRAM TO CRUNCH RAMAN DATA’//’ DO YOU WANT

1 INITIAL DIALOGUE 7’)

FORMAT(’ INPUT FILE ‘)

FORMAT(' OUTPUT FILE ’)

FORMAT(’ MIN FREQUENCY = ’,F10.4/’ MAX FREQUENCY" '.F10.4/
1’ SPACING BETWEEN POINTS 3 ’.F10.4)

FORMAT(’ OPTIONS FOR THIS RUN AREs'f’ PLOT: SMOOTH:

1 BASELINE CORRECTION: NORMALIZE;’/’ EXPAND: PRINT; TRANSLATE
2 TO E FORMAT: PEAK LOCATE; OR.SIGNAL AVERAGE’/

3’ WHAT IS YOUR.CHOICE?’)

FORMAT(’ ADD OR SUBTRACT? ’)

FORMAT(’ STRIP CHART OR TERMINAL7’)

FORMAT(’ CRUNCH. MOVE. OR DATCOL ?’)

END

SUBROUTINE RDAT.FT

SUBROUTINE RDAT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

OOOOOOODOOOOOOOO

SUBROUTINE TO READ ONE LINE OF DATA FROMTTHE INPUT FILE AND
BRANCH TO THE APPROPRIATE ROUTINE.

COMMON VARIABLES USED
IBASE BASELINE CORRECTION BRANCHING PARAMETER

INORM NORMALIZATION BRANCHING PARAMETER
IPST PLOT STARTING BRANCHING PARAMETER

DEVI INPUT DEVICE

FILEI INPUT FILE

X CURRENT FREQUENCY
Y CURRENT COUNTS/SEC.

XMIN MINIMUM FREQUENCY
XMAX' MAXIMUM FREQUENCY
YMAX MAXIMUM COUNTS/SEC.

RDAT.

C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C

C
C
C
C
C
C
C
C
C
C
C
C
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

(ll-1303”“

eunuch

118

CONT.

ITYPE BRANCHING PARAMETER
IPLOT PLOT BRANCHING PARAMETER
IDONE TEST FOR END

INTERNAL VARIABLES

IPEND FLAG FOR END OF PLOT

YSC Y STORAGE FOR NORM
B SUM STORAGE FOR BASE
NT TOTAL NUMBER OF POINTS READ IN

IVAL CHARACTER STORAGE
ISTEP NUMBER OF STEPS/POINT ON STRIP CHART
IP PLOT TYPE STORAGE

SUBROUTINES CALLED

IOPEN(DEV.FILE)
PLOT(ISTEP)
CHAIN
BASE(B,NT)
NORM(SCALE.YSC)
EXPAND

SCEND

LABEL

OCLOSE

BELL
YESNO(IVAL)
PRINT
KOHEKIIDUM)
PEAKS(XP.YP.NP)

STEPHEN M. GREGORY
APRIL 12. 1978

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
COMMON XMIN.XMAX.YMIN.YMAX.DELX.ITYPE.DEVI.DEV2.FILE1.FILE2.

1 IPLOT,IDONE,X.Y.IPST.IBASE.INORM.NTST.ISIG
DIMENSION B(6).YSC(5),XDAT(8).YDAT(8),XP(21).YP(21)

READ IN DATA POINTS ONE AT A TIME

IPEND=0

IBASE=1

INORM;0

IPST%1

ITRAN=1

NP=1

DO 1 1:1,5
YSC<IJ=0.

D0 2 I=1.6

B(I)=0.

GO TO (3,16.3.3,19,2o.3.22.3)ITYPE
CALL IOPENtnEV1,FILEl)
NT:0

READ(4.100) X.Y
CALL KCHEKtIDUM)
IF(IDUM)6.6.5
WRITE(1.101) X.Y
CALL YESNOtIVAL)
IF(IVAL-89)36.6,36
IF(X)24.7.7
IF(XFXNJN)4.9.9
IF(X-XMAXJ4.24.24
NT=NT+1

119

RDAT. CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C BRANCH

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
GO TO (10.16.17.18.19.20.21.22.23) ITYPE
10 IF(IPEND)11.11.15
11 IF(YMAXPY)12.13,13
12 YMAX=Y
13 IF(YMIN-Y)8.8.l4
14 YMIN=Y
GO TO 8
15 CALL PLOT(ISTEP.IP)
GO TO 8
16 CALL CHAIN( ’SMOOTH’ )
GO TO 36
17 CALL BASE(B.NT)
GO TO 8
18 CALL NORM(SCALE.YSC)
GO TO 8
19 CALL EXPAND
IF(ITYPE-l)24.3.24
20 CALL CHAIN(’SIGAV’)
GO TO 36
21 CALL PRINT
GO TO 8
22 CALL CHAIN(’MERGE’)
GO TO 8
23 CALL PEAKS(XP.YP.NP)
GO TO 8
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC'
C

C BRANCH TO TIE UP LOOSE ENDS BEFORE RETURNING TO CALLING
C ROUTINE.
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
24 GO TO (23.36.30.34.36.36.36.36.36) ITYPE

25 IF(IPEND)26.26,27
26 IPEND=1
GO TO 3
27 IF(IPLOT-1)28.28.29
28 - CALL SCEND
GO TO 36
29 CALL BELL
CALL LABEL
GO TO 36
30 GO TO (33.31.31) IBASE
31 XDONE=~1000.
YDONE=0.

WRITE(4,100) XDONE.YDONE
32 CALL OCLOSE
GO TO 36
33 IBASE=2
CALL BELL
WRITE(1.102)
CALL EXPAND
ITYPE=4
GO TO 3
34 IF(INORM)35.35.31
35 INORMfil
GO TO 3
36 CALL BELL
WRITE(1.103)
CALL YESNOIIVAL)
IF(IVAL-89)33.37.38
37 IDOIE=1
38 RETURN

RDAT.

120

CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C
C

FORMAT STATEMENTS

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

100
101

102
103

FORMAT(2A6)

FORMAT(’ CURRENT FREQUENCY IS ’,F10.4/’ CURRENT COUNTS/SEC
1 ARE ’.E10.4/’ DO YOU WANT TO CONTINUE ?’)

FORMAT(’ CHANGE SCALE TO SUBTRACT BASELINE’)

FORMAT(’ DONE ? ’)

END

SUBROUTINE PLOT.FT

SUBROUTINE PLOT(ISTEP.IP)

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

00000000OOODOODOOOOOOOOODOOD

OOOOODOOOOOOOOOODO

SUBROUTINE WILL PLOT OUT A DATA FILE 0N EITHER.THE STRIP CHART
RECORDER.IF IPLOT31. OR.ON THE TERMINAL IF IPLOT=2

IF THE PLOT IS MADE ON THE TERMINAL. THEN LABEL IS ENTERED

TO USE THE CROSSHAIRS TO LABEL INTERESTING FEATURES OF THE
PLOT. A TERMINAL PLOT'CAN EITHER BE A LINE PLOT OR A POINT
PLOT.

COMMON VARIABLES USED

IPLOT BRANCHING PARAMETER

IPST START PARAMETER.FOR STRIP CHART
Y CURRENT COUNTS/SEC.

X, CURRENT FREQUENCY

YMAX MAXIMUM COUNTS/SEC.

YMIN MINIMUM COUNTS/SEC.

XMAX MAXIMUM FREQUENCY

XMIN MINIMUM FREQUENCY

DELX SPACING BETWEEN DATA POINTS

INTERNAL VARIABLES

IY INTEGER Y VALUE

IX INTEGER X VALUE

ISTEP INTERVAL BETWEEN POINTS 0N RECORDER
STEMP TEMPORARY FLOATING ISTEP

AX TEMPORARY FLOATING IX
AY TEMPORARY FLOATING IY
IP 1 FOR LINE PLOT

-1 FOR POINT PLOT
SUBROUTINES CALLED

SCST(IY)
SCPLT(ISTEP.IYO
ERASE
FDIS(I.IX.IY)
LIMIT<IL.RVAR.IH)
LETIN(IVAL,IC,IG)
BELL

HOME

STEPHEN M. GREGORY
APRIL 12. 1978

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

COMMON XMIN.XMAX.YMIN.YMAX.DELX.ITYPE.DEV1.DEV2.FILEI.FILE2.
1 IPLOT.IDONE.X.Y,IPST.IBASE,INORM.NTST.ISIG
GO TO (1.4)IPLOT

121
PLOT. CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C PLOTS ON RECORDER
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
1 GO T0 (2.3) IPST
2 IPST‘2

CALL BELL

READ(1,100) STEP

CALL ERASE

STEMP=DELXX300./STEP

ISTEP=LIMIT(0.STEMP.2047)

AY3(Y;YMIN)*2047./(YMAXFYMIN)

IY’LIMIT(0.AY.2047)

CALL SCST(IY7

RETURN
3 AY3(YSYMIN)*2O47./(YMAXFYMIN)

IY=LIMIT(0.AY,2047)

CALL SCPLT<ISTEP.IY)

RETURN
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C PLOTS ON TERMINAL
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
4 GO TO (5.17) IPST'
5 IPST=2

CALL BELL
6 WRITE(1.101)

CALL LETIN(IVAL.IC.IG)

IF(IC)8.8.7
7 STOP
8 IF(IG)9.9.6
9 IF(IVAL-1039)10.ll.10
10 IF(IVAL-777)6.l2.6
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C POINT PLOT
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
11 IP=-l

GO TO 13
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C LINE PLOT
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
12 IP=1
13 READ(1.102) XMARK

CALL ERASE
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C SET UP X AXIS MARKINGS

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
XM=XMARK*1024./(XMAXFXMIN)
MARK?LIMIT(I.XM.1024)
CALL FDIS(0.0.0)
IX=-MARK
14 IX=IX+MARK
IF(IXF1024)15.15.16
15 CALL FDIS(I.IX.0)
CALL FDIS(I.IX.10)
CALL FDIS(1,IX.0)
GO TO 14
16 CALL FDIS(0.0.0)

122

PLOT. CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C PLOT DATA

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
17 AX=(XFXMIN)*1024./(XMAXFXMIN)

IX=LIMIT(0.AX.IO24)

AY=(Y‘YMIN)*768./(YMAX-YMIN)

IY=LIMIT(0.AY.768)

CALL FDIS(IP.IX.IY)

CALL HOME
RETURN
ccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccccc
c
c FORMAT 5'11:er
c

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
100 FORMAT(’ SPACING ON RECORDER IN CM-l/INCH = ‘.F10.4)
101 FORMAT(’ POINT OR LINE PLOT 7’)
102 FORMAT(’ MARKINGS IN CMrl 3 '.F10.5)
END

PROGRAM'SMOOTH.FT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
PROGRAM SMOOTH

PROGRAM DOES A 17 POINT SMOOTH 0N REAL DATA. THIS PROGRAM IS
USED VITH THE RAMAN PACKAGE. IT IS CALLED BY'THE STATEMENT

CALL CHAIN('SMOOTH')
COMMON VARIABLES USED

DEV! INPUT DEVICE

FILEl INPUT FILE

DEV2 OUTPUT DEVICE

FILE2 OUTPUT FILE

XMAX MAXIMUM FREQUENCY

XMIN MINIMUM FREQUENCY

DELX SPACING BETNEEN DATA POINTS

INTERNAL VARIABLES

NP NUMBER OF DATA POINTS

NR NUMBER OF DATA POINTS FOR EACH PASS
XNU FREQUENCY VALUES

YCN COUNTS

P SMOOTHING POLYNOMIAL

SUM SMOOTHING FACTOR

IVAL CHARACTER STORAGE
IDUM CHECK FOR.INTERRUPTION

SUBROUTINES CALLED

IOPEN(DEV,FILE)
OOPEN(DEV.FILE)
OCLOSE

CHAIN

BELL
YESNO(IVAL)
KCHEK(IDUM)

GOODOD0000000000OOOOOOOOOOODOOOOOOOOOOO

123

SMOOTH. CONT.

C STEPHEN M. GREGORY
C APRIL 12. 1978

C

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
COMMON XMIN.XMAX.YMIN.YMAX.DELX.ITYPE.DEV1.DEV2.FILE1.FILE2.
I IPLOT.IDONE.X.Y.IPST.IBASE.INORM,NTST.ISIG.XNU.YCN
DIMENSION XNU(512).YCN(512).P(17)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
c .
C OPEN DATA FILES AND READ IN

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
CALL IOPEN(DEV1.FILE1)
CALL OOPEN(DEV2.FILE2)
NP=IFIX((XMAXFXMIN)/DELX)+I
IF(NP-5l2)2,2.3
NR;NP
GO TO 4
NRF512
DO 5 I=I.NR
READ(4,100) XNU(I),YCN(I)
CALL KCHEK(IDUM)
IF(IDUM)7.7.6
WRITE( 1.101)XNU( I),YCN(I)
CALL YESNO(IVAL)
IF(IVAL-89)16.7.16
7 N=Ner6

DO 8 I=1,16
8 P( I+1)=YCN( I)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C .

C SMOOTH

Gil-I803 NH

0‘

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
DO 10 J=I.N
DO 9 K=l.l6
9 P(K)=P(K}l)
P(17)=YCN(J+16)
SUM=43.*P(9)+42.*(P(8)+P(IO))+39.*(P(7)+P(ll))+34.*(P(6)+P(12))
SUM=SUM+27.*(P(5)+P(13))+18.*(P(4)+P(14))+7.*(P(3)+P(l5))
SUM=SUMP6.*(P(2)+P(16))-21.*(P(1)+P(I7))
IO YCN(J)=SUM/323.
L=N
DO 11 K=l,N
YCN( L+8) =YCN( L)
11 L=L-1
D0 12 K=l.8
J=N+8+KF1
L=N+K-l
I2 YCN( J) = YCN( L)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C READ ONTO OUTPUT FILE
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
DO 13 I=1.NR
l3 WRITEC4.IOO) XNU(I),YCN(I)
IF(NRPNP)14.15.15
l4 NP=NP-NR
GO TO I
15 XDONE=-IOOO.
YDONE=O.
WRITE(4.IOO) XDONE.YDONE
CALL OCLOSE
CALL BELL
I6 WRITE( I, 102)
CALL YESNO(IVAL)
IF(IVAL-89)17,25,17
l7 WRITE(1,103)

124

SMOOTH. CONT.

CALL LETIN(IVAL.IC.IG)
IF(IC-l)18,25.18
18 IF(IG—I)l9.l7.l9

l9 IF(IVAL-210)20,22.20
2O IF(IVAL-847)21.23,21
21 IF(IVAL-257)17,24.l7

22 CALL ERASE

CALL CHAIN('CRUNCH’)
23 CALL ERASE

CALL CHAIN('MOVE’)
24 CALL ERASE

CALL CHAIN(’DATCOL’)
25 STOP
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C FORMAT STATEMENTS
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
100 FORMAT(2A6)
101 FORMAT(’ CURRENT FREQUENCY IS ’.F10.4/' CURRENT COUNTS/SEC

I ARE '.ElO.4/’ DO YOU WANT TO CONTINUE ?’)
102 FORMAT(’ DONE ? ')
103 FORMAT(’ CRUNCH. MOVE. OR DATCOL 7’)

END

SUBROUTINE BASE.FT

SUBROUTINE BASECB.NT)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

SUBROUTINE TO CORRECT FOR A LINEAR.BASELINE DRIFT

AFTER GOING THROUGH THE FIRST HALF OF THE PROGRAM. EXPAND
IS ENTERED SO THAT THE FREQUENCY LIMITS CAN BE CHANGED TO
INCLUDE ANY PEAKS THAT NEED TO HAVE THE BASELINE ADJUSTED

COMMON VARIABLES USED

DEV2 OUTPUT DEVICE
FILE2 OUTPUT FILE

IBASE BRANCH PARAMETER

X CURRENT FREQUENCY
Y CURRENT COUNTS/SEC.

INTERNAL VARIABLES

B USED TO HOLD ALL SUMS

D DENOMONATOR FOR SLOPE CALC
YN NEW VALUE OF Y

NT NUMBER OF POINTS

SUBROUTINES AND FUNCTION SUBPROGRAMS REQUIRED
OOPEN(DEV,FILE)

STEPHEN M. GREGORY
APRIL 12. 1978

0000000OODOOOOOOOOOOOODDOOOOO

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
COMMON XMIN.XMAX.YMIN.YMAX.DELX.ITYPE.DEV1.DEV2.FILE1.FILE2.
l IPLOT.IDONE.X.Y.IPST.IBASE.INORM.NTST.ISIG
DIMENSION 8(6)
GO TO (1,2,3) IBASE

125

BASE. CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

8(1) IS THE SUM OF ALL X. B(2) IS THE SUM OF ALL Y.
3(3) IS THE SUM OF ALL X*X. B(4) IS THE SUM OF ALL X*Y}
8(5) 18 THE SLOPE. B(6) IS THE INTERCEPT

00000

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
I B(1)=B(l)+x

B(2)=B(2)+Y

B(3)=B(3)+X*X

B(4)=B(4)+X$Y

RETURN
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

C
C CALCULATE SLOPE AND INTERCEPT
C
CCCCCCCCCCCCgCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
2 IBASE= .
D=FLOAT(NT)*B(3)-B(1)*B(l)
B(5)=(FLOAT(NT)*B(4)-B(1)*B(2))/D
B(6)=(B(3)*B(2)-B(l)*B(4))/D
CALL OOPEN(DEV2.FILE2)
3 YN=YLB(5)*XFB(6)
WRITE(6.100) X,YN
RETURN
100 FORMAT(2A6)
END

SUBROUTINE NORM.FT

SUBROUTINE NORM(SCALE,YSC)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

SUBROUTINE WILL NORMALIZE ONE OR MORE RAMAN PEAKS
IT USES THE FIVE POINES AROUND YMAX TO CALCULATE THE SCALING
FACTOR

COMMON VARIABLES USED

INORM BRANCHING PARAMETER
NTST TEST FOR FINISH

Y CURRENT COUNTS/SEC.
X CURRENT FREQUENCY
DEV2 OUTPUT DEVICE

FILE2 OUTPUT FILE

INTERNAL VARIABLES

YSC STORAGE FOR Y VALUES USED TO CALCULATE SCALE
YMD MIDPOINT OF YSC
YI TEMPORARY Y STORAGE

SCALE SCALING FACTOR
SUBROUTINES CALLED
OOPEN(DEV,FILE)

STEPHEN M. GREGORY
APRIL 12. I978

00000000000000000000000000000

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
COMMON XMIN,XMAX.YMIN.YMAX.DELX.ITYPE.DEVI.DEV2.FILE1.FILE2.
l IPLOT,IDONE.X.Y,IPST.IBASE.INORM,NTST,ISIG
DIMENSION YSC(3)
IF(INORM)1.1.11

126

NORM. CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C CALCULATE SCALING FACTOR
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
l IF(NTST)9.2.2
2 D0 3 I=l.4
3 YSC(I)=YSC(I+I)
YSC(5)=Y
YMD‘YSCCI)
D0 5 1:2.5
'YI=YSC(I)
IF(YI-YMD)5.5,4
YMD=YI
K=I
CONTINUE
IF(K'3)99699
IF(YMD-YMAX39.7.IO
NTST=I
SCALE=0.
D0 8 I=l.5
SCALE=SCALE+YSC(I)
SCALE=SCALE/5.
WHITE(I.100) SCALE
9 RETURN
IO YMAX:YMD

GO TO 7
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C NORMALIZE
C .
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
Il IF(NTST)13.14.12
12 NTSTi-l

CALL OOPEN(DEV2.FILE2)
13 YN=YVSCALE

WRITE(4.IOI) X.YN
14 RETURN
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

“100$

m

C FORMAT STATEMENTS
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
100 FORMAT(’ SCALING FACTOR 3 ’.F10.4)
101 FORMAT(ZAG)

END

SUBROUTINE EXPAND.FT

SUBROUTINE EXPAND
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

SUBROUTINE TO CHANGE MAXIMUM AND MINIMUM VALUES OF BOTH
FREQUENCY AND COUNTS/SEC

AFTER LEAVING THIS ROUTINE SUBROUTINE PLOT CAN BE ENTERED USING
THE NEW VALUES AND PLOTTING ON THE TERMINAL

COMMON VARIABLES USED:

XMIN MINIMUM FREQUENCY VALUE
XMAX MAXIMUM FREQUENCY VALUE
YMIN MINIMUM COUNTS/SEC.
YMAX' MAXIMUM COUNTS/SEC.
ITYPE BRANCHING PARAMETER
IPLOT PLOTTING PARAMETER

00000000000000

127

EXPAND. CONT.

INTERNAL VARIABLES
'IVAL USED FOR CHARACTER STORAGE
SUBROUTINES CALLED

ERASE
BELL

C
C
C
C
C
C
C
C YESNO(IVAL)
C
C
C
C STEPHEN M. GREGORY
C APRIL 12. 1978
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
COMMON XMIN,XMAX.YMIN,YMAX.DELX.ITYPE.DEVI.DEV2.FILE1.FILE2.
1 IPLOT.IDONE.X.Y.IPST.IBASE.INORM.NTST.ISIG
CALL ERASE
CALL BELL
WRITE(1.100) XMIN.XMAX.YMIN,YMAX
WRITE(1.101)
CALL YESNO(IVAL)
IF(IVAL-89)2.1.2
l READ(1,102) XMIN
2 WRITE(1.103)
CALL YESNO(IVAL)
IF(IVAL—89)4.3.4
3 READ(1.102) XMAX
4 WRITE(1.104)
CALL YESNO(IVAL)
IF(IVAL-89)6,5.6
5 READ(1.102) YMIN
6 WRITE(I.105)
CALL YESNO(IVAL)
IF(IVAL-89)8.7,8
7 READ(1,102) YMAX
8 WRITE (1.106)
CALL YESNO(IVAL)
IF(IVAL-89)10.9.10

9 ITYPE=1
IPLOT22

10 CALL ERASE
RETURN

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C FORMAT STATEMENTS
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
100 FORMAT(’ CURRENT VALUES’/’ MINIMUM FREQUENCY = ’,FIO.4/
1’ MAXIMUM FREQUENCY = '.F10.4/' MINIMUM COUNT = '.El5.8/
2’ MAXIMUM COUNT = ’.E15.8)
101 FORMAT(’ WHICH ONES DO YOU WANT TO CHANGE ?’/' MINIMUM
1 FREQUENCY 7’)
102 FORMAT(' ? ’.FIO.4)
103 FORMAT( ’ MAXIMUM FREQUENCY ?’ )
104 FORMAT(’ MINIMUM COUNT/SEC ?’)
105 FORMAT(’ MAXIMUM COUNTVSEC ?’)
106 FORMAT(’ DO YOU WANT TO PLOT EXPANDED RESULTS ?’)
END

128

PROGRAM SIGAV.FT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

0000000000

0000000000000000000000000000000000000

PROGRAM SIGAV

PROGRAM WILL EITHER ADD OR SUBTRACT UP TO 100 SETS OF
SPECTRA

ISIG = 1 FOR ADDITION
2 FOR SUBTRACTION

COMMON VARIABLES USED

DEV2 OUTPUT DEVICE

FILE2 OUTPUT FILE

DEVI FIRST INPUT DEVICE

FILEI FIRST INPUT FILE

ISIG BRANCHING PARAMETER

XMIN MINIMUM FREQUENCY

XMAX MAXIMUM FREQUENCY

DELX SPACING BETWEEN DATA POINTS

INTERNAL VARIABLES

NDAT NUMBER OF DATA FILES TO BE AVERAGED
DEV DEVICE EACH DATA FILE IS ON

FIL STORAGE FOR FILE NAMES

XDAT TEMPORARY FREQUENCY STORAGE

YDAT TEMPORARY Y STORAGE

XTEMP TEMPORARY STORAGE FOR XMIN

XS ARRAY FOR FREQUENCY STORAGE

YS ARRAY FOR COUNT/SEC

IDUM CHECK FOR INTERUPTION

SUBROUTINES CALLED

OOPEN(DEV,FILE)
IOPEN(DEV,FILE)
BELL

ERASE

OCLOSE

YESNO(IVAL)
FILE(DEV.FIL.IMODE)
KCHEK(IDUM)

STEPHEN M. GREGORY
APRIL 12. I978

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

COMMON XMIN.XMAX.YMIN.YMAX.DELX,ITYPE.DEV1.DEV2.FILE1.FILE2.
1 IPLOT.IDONE.X,Y.IPST,IBASE.INORM,NTST.ISIG
DIMENSION DEV(100).FIL(100).XS(300).YS(300)

CALL OOPEN(DEV2.FILE2)

CALL BELL

READ(1.IOO) NDAT

DEV(1)=DEV1

FIL(1)=FILE1

DO 2 I=2.NDAT

IMODE=I

WRITE(1.101) I

CALL FILE(DEV(I).FIL(I).IMODE)

IMODE=IMODE+3

GO TO (I9,27.l.2)IMODE

CONTINUE

CALL ERASE

XTEMP=XMIN

GO TO (3.28) ISIG

129
SIGAV, CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C ADDITION

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
3 D0 4 131,300
4 YS(I)=0.
D0 13 I’lgNDAT
CALL IOPEN(DEV(I),FIL(I))
J=l
5 READ(4.IO2) XDAT.YDAT
CALL KCHEK(IDUH)
IF(IDUH)7.7,6
WRITE(I.103)I.XDAT.YDAT
CALL YESNO(IVAL)
IF(IVAL-89)18.7,18
IF(XDAT)IO.8.8
IF(XDAT-XMIN)5.9.9
IF(XDAT-XHAX310.I3,I3
XS(J)=YDAT
YS(J)=YS(J)+YDAT
IF(XDAT)I3,11,II
J=J+l
GO TO 5
13 CONTINUE
XMIN=XDAT+DELX
DO 14 I=l.J
YI‘YS( I)
YI=YI/FLOAT( NDAT)
14 WRITE(4.102) XS(I).YI
IF(XDAT-XMAX) 15.16.16
15 IF(XDAT)16.3.3
16 XMIN= XI'EI‘IP
I? CALL OCLOSE
CALL BELL
18 WRITE(I.104)
CALL YESNO(IVAL)
IF(IVAL-89)I9.27,l9
l9 WRITE(I.105)
CALL LETIN(IVAL.IC.IG)
IF(IC-1)20.27.20

Moms] 0
9

“H
[OH

20 IF(IG-l)2l.l9.2l

21 IF(IVAL-210)22,24,22
22 IF(IVAL-847)23,25,23
23 IF(IVAL-257)l9.26.l9

24 CALL ERASE

CALL CHAIN(’CRUNCH')
25 CALL ERASE

CALL CHAIN(’MDVE')
26 CALL ERASE

CALL CHAIN(‘DATCOL’)
27 STOP
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C SUBTRACTION

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

28 CALL IOPEN(DEV(1).FIL(1))
J=l

29 READ(4,102) XDAT,YDAT
CALL KCHEK(IDUM)
IF(IDUM)31.31.3O

30 WRITE(I.103)I.XDAT.YDAT
CALL YESNO(IVAL)
IF(IVAL-89)18,31,18

31 IF(XDAT)33.32.32

32 IF(XDAT-XMINJQ9g33.33

33 XS(J)=XDAT

SIGAV.

34
35
36

37

38

39

40
41
42

43

44
45

130

CONT.

YS(J)=YDAT
IF(XDAT)37.34.34
IF(XDAT-XMAX)35.37.37
IF(J-300)36.37.37

J=J+l

GO TO 29

DO 42 I=2.NDAT

CALL IOPEN(DEV(I).FIL(I))
DO 42 KFI,J

READ(4.102) XDAT,YDAT
CALL KCHEK(IDUM)
IF(IDUM)40.40.39

WRITE( I. 103) I.XDAT.YDAT
CALL YESNO(IVAL)
IF(IVAL-89)18.40.18
IF(XDAT)42.41.41
IF(XDAT-XMIN)38.42.42
YS(K)=YS(K)-YDAT
XMIN=YDAT+DELX

DO 43 K=I.J
WRITE(4.102) XS(K).YS(KD
IF(XDAT)45.44.44
IF(XDAT-XMAX)37.45.45
XMIN=XTEMP

GO TO 17

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

C
C

FORMAT STATEMENTS

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

100
101
102
103

104
105

FORMAT(’ HOW MANY DATA FILES ? '.I3)

FORMAT(’ INPUT FILE ’.I2)

FORMAT(2A6)

FORMAT(’ FILE ’ ,I3/’ CURRENT FREQUENCY IS ',F10.4/ ‘ CURRENT
I COUNTS/SEC ARE ’.E10.4/’ DO YOU WANT TO CONTINUE ?‘)
FORMAT(’ DONE ?’)

FORMAT(' CRUNCH. MOVE. 0R DATCOL ?')

END

SSUBROUTINE PRINT.FT

SUBROUTINE PRINT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC'

000000000000000000

SUBROUTINE T0 PRINT OUT A LINE OF DATA ON THE TTY
NORMALLY USED TO CHECK THE DATA THAT IS BEING WRITTEN
ON THE OUTPUT FILE.

COMMON VARIABLES USED

X CURRENT FREQUENCY
Y CURRENT COUNTS/SEC.

SUBROUTINES USED
NONE

STEPHEN M. GREGORY
MAY 16. 1977

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

COMMON XMIN.XMAX,YMIN,YMAX.DELX.ITYPE.DEV1,DEV2.FILEI.FILE2,
I IPLOT.IDONE.X.Y.IPST.IBASE.INORM.NTST.ISIG

131

PRINT. CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C PRINT OUT X AND Y
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
WRITE(I.IOO) X}Y
100 FORMAT(IH ,F10.4,10X.E15.8)
RETURN
END

PROGRAM MERGE.FT

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
PROGRAM MERGE

PROGRAM TO MERGE FILES TOGETHER. PROGRAM CAN HANDLE EITHER
E OR A FORMATTED FILES, WITH OR WITHOUT DATA TAGS.
THE PROGRAM NILL MERGE UP TO 10 INPUT FILES

VARIABLES USED

NFILE NUMBER.OF INPUT FILES
XMIN MINIMUM X ARRAY

XMAX MAXIMUM X ARRAY

DEV INPUT DEVICE ARRAY

FIL INPUT FILE ARRAY

IMODE I/O MODE AND RETURN FLAG

DEVO OUTPUT DEVICE

FILO OUTPUT FILE

IVAL CHARACTER STORAGE

IC FLAG FOR CONTROL C

IG FLAG FOR CONTROL G

X X VALUE TO BE TRANSFERED

Y Y VALUE TO BE TRANSFERED
XEND FINAL X VALUE

YEND FINAL Y VALUE

ITG FLAG FOR OUTPUT FILE DATA TAG
TG OUTPUT DATA TAG

ITAG FLAG FOR INPUT FILE DATA TAG
OTG OLD (INPUT FILE) DATA TAG
IDUM FLAG FOR INTERRUPT

SUBROUTINES CALLED

FILE(DEV,FIL.IMODE)
OOPEN(DEV.FIL)
LETIN(IVAL.IC.IG)
IOPENtDEV.FIL)
YESNO(IVAL)

OCLOSE

KCHEK(IDUM)

C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C STYTTHHIIM. GREIKHPY
C APRIL 12. 1978
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
DIMENSION DEV(10),FIL(10).XMIN(10),XMAX(10)
l READ(1.IOO) NFILE
DO 2 I=l.NFILE
WRITE(1.101) I

2 BEAD(1.102) XMIN(I),}C’IAX(I)
DO 4 I=1.NFILE
3 WRITE(1.101) I

IMODE=1

132

MERGE. CONT.

CALL FILE(DEV(I),FIL(I).IMODE)

IMODE=IMODE+3

GO TO (69,78,3,4) IMODE
4 CONTINUE
5 WRITE(1.103)

IMODE=0

CALL FILE(DEVO,FILO.IMODE)
IMODE=IMODE+3
GO TO (69.78,5,6) IMODE

6 CALL OOPEN(DEVO,FILO)

7 WRITE(1,104)
CALL LETIN(IVAL.IC.IG)
IF(IC-l)8.78.8

8 IF(IG-1)9.69,9

9 IF(IVAL-65)10.13.10

10 IF(IVAL-69)11.22,ll

ll IF(IVAL-32l)l2.36,12

12 IF(IVAL-325)7,49,7
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C A TO A FORMAT

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
13 CALL ERASE
DO 20 I=l.NFILE
CALL IOPEN(DEV(I),FIL(I))
I4 READ(4,105) X.Y
CALL KCHEK(IDUM)
IF(IDUM)17.17,15
15 WRITE(1.106) I,X,Y
CALL YESNO(IVAL)
IF(IVAL-89)69,16,69
16 CALL ERASE
17 IF(X)20.18.18
18 IF(X‘XMIN(I))14.19.19
19 WRITE(4.105) X.Y
IF(X-XMAX(I))14.20.20
20 CONTINUE
21 XEND=-1000.

YEND=0.

WRITE(4.105) XEND.YEND

GO TO 68
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C A TO E FORMAT
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
22 WRITE(1.107)

CALL YESNO(IVAL)

IF(IVAL-89)23.24,23

23 ITG=1
GO TO 25
24 ITG=2

READ(1,108) TC
25 CALL ERASE
DO 35 I=1,NFILE
CALL IOPEN(DEV(I),FIL(I))
26 READ(4,105) X.Y
CALL KCHEK(IDUM)
IF(IDUM)29.29.27
27 WRITE(1,106) I.X.Y
CALL YESNO(IVAL)
IF(IVAL-89)69.28.69
28 CALL ERASE

29 IF(X)35.30.30
30 IF(XFXMIN(I))26.31.31
31 GO TO (32.33) [TC

32 WRITE(4,109) X,Y
GO TO 34

133

MERGE, CONT.

33 WRITE(4.110) TG.X.Y

34 IF(XFXMAX(I))26.35.35
35 CONTINUE

GO TO 68
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C E TO A FORMAT
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
36 WRITE(1.111)
CALL YESNO(IVAL)
IF(IVAL-89)37,38.37
37 ITAG=1
GO TO 39
38 ITAG=2
39 CALL ERASE
DO 48 I=1,NFILE
CALL IOPEN(DEV(I).FIL(I))
40 GO TO (41.42) ITAG
41 READ(4.109) X.Y
GO TO 43
42 READ(4,110) OTGLX.Y
43 CALL KCHEK(IDUM)
IF(IDUM)46.46.44
44 VRITE(1.106) I.X.Y
CALL YESNO(IVAL)
IF(IVAL-89)69,45,69.
45 CALL ERASE
46 IF(XFXMIN(I))40.47,47
47 WRITE(4.105) X,Y
IF(XFXMAX(I))40.48.48
48 CONTINUE
GO TO 21
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C E TO E FORMAT
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
49 WRITE(1,111)
CALL YESNO(IVAL)
IF(IVAL-89)50.51.50

50 ITAG=1
GO TO 52
51 ITAG=2

32 WRITE(1.107)
CALL YESNO(IVAL)
IF(IVAL-89)53.54.53

53 ITG=1
GO TO 55
54 ITG=2

READ(1.108) TC
55 CALL ERASE
DO 67 I=1.NFILE
CALL IOPEN(DEV(I).FIL(I))
56 GO TO (57,58) ITAG
57 READ(4.106) X.Y
GO TO 59
58 READ(4.110) OTG.X,Y
59 CALL KCHEK(IDUM)
IF(IDUM)62.62.60
60 WRITE(1.106) I.X.Y
CALL YESNO(IVAL)
IF(IVAL-89)69.61.69
61 CALL ERASE
62 IF(X‘XMIN(I))56.63,63
63 GO TO (64.65) ITG
64 WRITE(4.109) X.Y
GO TO 66
65 WRITE(4.110) TG.X,Y

134

MERGE. CONT.

66 IF(X-XMAX(I))56.67.67

67 CONTINUE
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C CLOSE FILES
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
68 CALL OCLOSE
69 WRITE(1.112)
CALL YESNO(IVAL)
IF(IVAL-89)70.78.70
70 WRITE(1.113)
CALL LETIN(IVAL.IC.IG)
IF(IC-l)71.78.7l

71 IF(IG-l)72.70.72
72 IF(IVAL-210)73,75.73
73 IF(IVAL-847)74.76.74

74 IF(IVAL-257)70.77.70
75 CALL ERASE
CALL CHAIN(’CRUNCH')
76 CALL ERASE
CALL CHAIN('MOVE’)
77 CALL ERASE
CALL CHAIN(’DATCOL')
78 STOP
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C FORMAT STATEMENTS

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

100 FORMAT(’ HOW MANY INPUT FILES ? ’,I2)

101 FORMAT(’ FILE ’.I2)

102 FORMAT(’ MIN X = ’.F10.4/' MAX X 3 ’.F10.4)

103 FORMAT(’ OUTPUT FILE’)

104 FORMAT(’ I/O OPTIONS ARE:’/’ A FORMAT TO A FORMAT (AA); A
1 FORMAT TO E FORMAT (AE);’/’ E FORMAT TO A FORMAT (EA):
2 E FORMAT‘TO E FORMAT (EE)'/’ WHAT IS YOUR CHOICE 7')

105 FORMAT(2A6) '

106 FORMAT(’ FILE ’.12/’ FREQUENCY = ’u"‘0.4/’ COUNTS/
lSEC = ‘.E10.4/’ DO YOU WANT TO CONTINUE 7’)

107 FORMAT(' IS THERE AN OUTPUT DATA TAG ?')

108 FORMAT(’ DATA TAG = ’.A2)

109 FORMAT(2E15.7)

110 FORMAT(A2.2E15.7)

111 FORMAT(’ IS THERE AN INPUT DATA TAG ?’)

112 FORMAT(’ DONE ?’)

113 FORMAT(' CRUNCH. MOVE. OR DATCOL ?’)
END

SUBROUTINE PEAKS.FT

SUBROUTINE PEAKS(XP.YP.NP)
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

SUBROUTINE TO FIND AND PRINT OUT THE VALUES OF ALL RAMAN
PEAKS THAT HAVE AN INTENSITY ABOVE A MINIMUM VALUE

COMMOM VARIABLES USED

IPST BRANCHING PARAMETER

YMIN MINIMUM COUNTS/SEC

X CURRENT FREQUENCY

Y CURRENT COUNTS/SEC

YMAX TOTAL COUNTS WHEN DATA WAS COLLECTED

000000000000

13S

PEAKS , . CONT.

INTERNAL VARIABLES
KP FREQUENCY ARRAY
YP COUNTS/SEC ARRAY
NP ARRAY POINTER

YTOP MAX COUNTS/SEC IN ARRAY
XTOP FREQUENCY OF YTOP

MAX POINTER FOR YTOP

YLOW MIN COUNTS/SEC IN ARRAY
YSQRT SQUARE ROOT OF YMAX
YDIFF YTOP - YLOW

STEPHEN M. GREGORY
APRIL 12. I978

0000000000000000

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

COMMON XMIN . XMAX. YMIN. YMAX. DELX. ITYPE. DEVI . DEV2 . F ILEI .F ILE2.

I IPLOT. IDONE. X. Y. IPST. IBASE. INORM, NTST. IS IG

DIMENSION XP( 21) .YP(21)

GO TO (1.2.5) IPST
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C FILL UP ARRAY
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
I READ (1.100) YMIN.YMAX
CALL ERASE
IPST=2
2 XP(NP)=X
YP(NP)=Y
IF(NP-2I)3.4.4
3 NP=NP+I
RETURN
4 IPST=3
GO TO 6
5 XP(21)=X
YP(21)=Y

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C

C FIND MAXIMUM AND MINIMUM IN ARRAY
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
6 YTOP=YP( l)

XTOP=XP( 1)

YLOW=YP( I)

DO 10 I=2.21
IF( YTOP-YP( I) )7.8.8
7 YTOP=YP( I)
XTOP=XP( I)
MAX=I
IF(YLOW-YP( 1)) 10.10.9
YLOW=YP( I)
0 CONTINUE
IF(YTOP-YMIN) 14.12.12
YSQRT= SQRT( YMAX)
YDIFF=YTOP-YLOW
IF(YDIFF-YSQRT)14. 13. 13
13 WRITE(1.101)XTOP.YTOP
14 DO 15 1:1.20
XP( I)=XP( 1+1)
15 YP(I)=YP( 1+1)
RETURN

#0“

“H

10)-

136

PEAKS. CONT.

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC-
C
C FORMAT STATEMENTS
C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
100 FORMAT(’ MINIMUM COUNTS/SEC FOR PEAK = ’.FIO.4.’ MAXIMUM COUNTS

1 FOR DATA SET = ’,F10.4)
101 FORMAT(’ FREQUENCY = ’.FIO.4.5X.’ COUNTS/SEC = ’,E15.8)

END

SUBROUTINE LABEL.FT

SUBROUTINE LABEL
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

C .

C SUBROUTINE TO LABEL POINTS ON THE TERMINAL

C HIT A CONTROL G TO RETURN TO CALLING PROGRAM

C CROSSHAIRS ARE PUT ON THE SCREEN AND A + [S PUT AT THE

C INTERSECTION OF THE CROSSHAIRS WHEN A CHARACTER ON THE KEYBOARD

C IS HIT. ALSO THE X AND Y VALUES OF THAT POINT ARE PRINTED

C OUT.

C

C COMMON VARIABLES USED

C

C XMAX MAXIMUM FREQUENCY

C XMIN MINIMUM FREQUENCY

C YMAX MAXIMUM COUNTS/SEC.

C YMIN MINIMUM COUNTS/SEC.

C

C INTERNAL VARIABLES

C

C NX' X COORDINATE OF CROSSHAIRS

C NY Y COORDINATE 0F CROSSHAIRS

C NC CHARACTER STORAGE

C XP FREQUENCY CORRESPONDING TO NX

C Y? COUNTS CORRESPONDING TO NY

C

C SUBROUTINES CALLED

C

C JOY(NX.NY.NC)

C FDIS(I.IX.IY)

C ALPHA

C HOME

C ERASE

C

C STEPHEN M. GREGORY

C MAY 16. 1977

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
COMMON XMIN.XMAX.YMIN.YMAX.DELX.ITYPE.DEVI,DEV2,FILEI.FILEZ.
I IPLOT,IDONE.X.Y.IPST.IBASE.INORM.NTST.ISIG

I CALL JOY(NX.NY.NC)
IF(NC-480)2.3.2

2 NX?NXFI4

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

C

C PUT + ON SCREEN

C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
CALL FDIS(0.NX+5,NY)
CALL FDIS(I.NX+5.NY)
CALL FDIS(O.NX.NY‘5)
CALL FDIS(I.NX.NY+5)
XP=FLOAT(NX)*(XMAX‘XMIN)/1024.+XMIN
YP=FLOAT(NY)*(YMAXéYMIN)/768.+YMIN

137

LABEL. CONT.

CALL FDIS( O. NX.NY)
CALL ALPHA
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC

C
C PRINT OUT X AND Y COORDINATES

C
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
WRITE(I.IOO) XP.YP

GO TO 1
3 CALL HOME

CALL ERASE

RETURN
CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
C
C FORMAT STATEMENTS
C

CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC
100 FORMAT(FIO.4.3X.E15.8)
END

APPENDIX D

PROGRAM LNSHP

A FORTRAN program that calculates the reorientational half-width

from the polarized and depolarized spectra of a Raman band.

138

139

PROGRAM LNSHP

PROGRAM LNSHP(INPUT.OUTPUT.RPLOT.TAPE60=INPUT.TAPE61=OUTPUT.
ITAPE10=RPLOT)

A PROGRAM TO OBTAIN A REORIENTATION LINESHAPE FOR A RAMAN LINE AND
COMPARE THIS LINESHAPE TO A LORENTZIAN. DATA IS READ AS
ANGSTROM.COORDINATES AND TRANSFERED TO WAVENUMBERS BEFORE BEING
PLOTTED OUT.

000000

DIMENSION X1(1024).Y(1024).C(3).TL(18),IFSMO(4)
COMMON/AMP/SCALE(8).ICF(8).RHO.POLEFF.GAIN(8)
COMMON/DATA/AXIS(I024)
COMMON/CONV/Q(4.1024).ERROR(4).SCALC(8)
COMMON/SPECT/S(4.1024)
COMMON/SEARCH/XHWDTH.XMSTEP.ISKIP

COMMON P(5.1024).D(1024).IGONE(1024)

READ IN DATA

000

READ (60.1000) NJOB
1000 FORMAT (1814)
DO 15 KCRP=1.NJOB
READ (60.1001) (TL(N).N=1.18)
I001 FORMAT (18A4)
READ (60.1000) NDATA.NPPS.NBASE.ISKIP
READC60.1000) (IFSMO(I).1=1.NDATA)
WRITE (61.1002) (TL(N).N=I.18)
1002 FORMAT (1H1.18A¢//)
WRITE (61.1003) NDATA.NPPS
1003 FORMAT (14H DATA CONTAINS,I4.2X.10HLINES WITH.14,2X.15HPOINTS PER
ILINE)
READ (60.1004) XHWDTH.XMSTEP
DO 15 KK=1.NDATA
READ (60.1004) GA1N(KED
1004 FORMAT (2El5.7)
DO 1 K=I.NPPS
I READ (60.1004) AXIS(K).S(KK.K)

REMOVE NOISE SPIKES

000

IF(IFSMO(KK).NE.1) GO TO 4
OLDPNT=S(KK,1)
OLDSLP=.O5
1DELETE=0
DO 3 K?1.NPPS
XNEWPNT= S( KK. 1C)
XNEWSLP=ABS(XNEWPNT-OLDPNT)
IF(XNEWSLP.EQ.O) XNENSLP=OLDSLP
FOS=OLDSLP*500.
IF(XNEWSLP.GT.FOS) GO TO 2
OLDSLP=XNEWSLP
OLDPNT=XNEWPNT
GO TO 3

2 XNEWSLP=OLDSLP
XNENPNT=OLDPNT
S(KK.K)=OLDPNT
IDELETE=1DELETE+I
IGONEtIDELETE) =K

3 CONTINUE
1F(IDELETE.NE.0) WRITE (61.1005) (IGONE(K).K?1.IDELETE)

1005 FORMAT (35H THE FOLLOWING POINTS WERE DELETED. /30(1X.13))

IF(IDELETE.GT.5) GO TO 15
CALL SMOOTH(KK.YPPS)

TAKE MAX VALUE FOR MDPNT

000

4 XMAX=S( KK. 1)
XMDPNT=AKIS( 1)
MDPNT=1
DO 5 K=2.NPPS

LNSHP.

5

000

6

7

8

9

10
C
C
C

l 006

11
12

13

I4-
15

140

CONT.

IF(S(KK.K).LE.XMAX) GO TO 5
XMDPNT=AXIS(K)

XMAX=S(KK.K)

MDPNT=K

CONTINUE

CALCULATE BASELINE

L=0

IUP=NPPS-NBASE

DO 6 K=1.NBASE

L=L+I

X1(L)=AXIS(K)-XMDPNT
Y(L)=S(KK.IO

DO 7 K=IUP.NPPS

L=L+l

X1(L)=AXIS(K)-XMDPNT
Y(L)=S(I(K.K)

NP=2*NBASE

CALL BASE( NP.XI.Y.C)

ICF( KK)=MDPNT
IF(KGRP.EQ.1.A.KK.EQ.1) READ (60.1004) RHO.POLEFF
DO 8 K=1.NPPS

S(KK.K)=S( KK.K)-C( l)*(AXIS(K)-XMI)PNT)-C(2)
BLCOR=S(KK. 1)

DO 9 K=2.NPPS
1F(BLCOR.LT.S(KK.IO) GO TO 9
BLCOR=S(1CK.K)

CONTINUE

DO 10 K=I.NPPS
S(IG(.K)=S(KK.K)-BLCOR

NORMALIZE
CALL NORM( S. K. NPPS . MDPNT.SCALE( K10)

WRITE(61. 1006) XMDPNT. SCALE( KK)
FORMAT( //28H AFTER NORMALIZATION AT. T44, I7HCENTER FREQUENCY: .FIO. 4

1.8X.19HTHE SCALING FACTOR=.E13.5)

SCALE€ KK) =SCALE( KK) *GAIN( KK)
GET 2 SPECTRA BEFORE ENTERING INTNCOR AND MINN

IF(KK.NE.I) GO TO 12

DO 11 K=I.NPPS

D(K)=S(KK.K)

GO TO 15

CALL INTNCOR(KK.NPPS)
IF(KK.NE.2) GO TO 14

DO 13 K=1,NPPS
S(I.IO=S(1.1()-(4-./3.)*S(KK,K)*SCALE(m/SCALE(1)
CALL NORI‘N S . 1. NPPS . MDPNT. XMAX)
CALL MINI“ KK.NPPS)

CONTINUE

STOP

END

141

SUBROUTINE PLOT

SUBROUTINE PLOT(J,N.NW)

C
C SUBROUTINE PLOT CAN PLOT OUT'UP TO SEVEN DATA SETS ON‘THE LINE
C PRINTER. * IS THE FIRST DATA SET AND F IS THE SEVENTH.
C J IS THE NUMBER OF DATA SETS AND N IS THE NUMBER OF DATA POINTS.
C T0 PRINT OUT PLOTTED DATA. SET NW = 3.
C TO WRITE DATA INTO A FILE NUMBERED 10. SET NW = 2.
C TO DO BOTH, SET NW = 4. TO DO NEITHER. SET NW = 1.
C

COMMON/DATA/AXIS(1024)

COMMON P(7.1024)

DIMENSION Y(121).D(10).NP(7)

DATA D/IH .lH+.1H=.IH*.IHA.IHB.1HC.1HD.1HE.IHF/

DATA TG/ZHRD/
C
C SET UP Y AXIS
C

YMAX=0.

YMIN=0.

DO 2 1=1.J

DO 2 K=1.N

IF(P(I.K).LE.YMAX) GO TO 1

YMAX=P(I.KD

1 IF(P(I.K).GE.YMIN) GO TO 2
YMIN=P(I.KD

2 CONTINUE
XMIN=AXIS(2)-AXIS(1)
WRITE<61.100) J.N.AXIS(1).AXIS(N).XMIN.YMIN.YMAX
100 FORMAT(1H1.28HSUBROUTINE PLOT PLOTTING'OUT.2X.I2.2X.14HFUNCTIONS W
11TH.2X.I4.2X.11HDATA POINTS/18H X AXIS GOES FROM .F9.2.2X.2HTO.
2F9.2.2X.11HBY STEPS 0F .F5.2/18H Y AXIS GOES FROM .F7.2.2X32HTO.
3F7.2//)

SET UP EACH LINE OF PLOT

000

D0 6 I=1.N
D0 3 KKK=1.121 .
3 Y(KKK)=D(1)
Y(1)=D(2)
D0 4 K:1.J
YP=(P(K.I)-YMIN)/(YMAX+YH1N)
YP=YP$120.+1.
4 NP(K)=IFIX(YP)
DO 3 K=1.J
Y(NP(K))=D(K+3)
IF(K.EQ.1) GO TO 5
1F(NP(K).EQ.NP(K%1)) Y(NP(K))=D(3)
1F(K.EQ.2) GO TO 5
IF(NP(K).EQ.NP(K&2)) Y(NP(K))=D(3)
IF(K.EQ.3) GO TO 5
IF(NP(K).EQ.NP(K+3)) Y(NP(K))=D(3)
IF(K.EQ.4) GO TO 5
IF(NPtK).EQ.NP(Kk4)) Y(NP(K))=D(3)
IF(K.EQ.5) GO TO 5
IF( NPtK).EQ.NP(K+5)) YINP(ED)=D(3)
IF(K.EQ.6) GO TO 5
1F(NP(K).EQ.NP(K+6)) Y(NP(K))=D(3)
5 CONTINUE
6 WHITE (61.101) (Y(NN).NN=1.121)
101 FORMAT(IH .121A1)
GO TO (11.9.7.7) NW
7 DO 8 1=1,N
8 WRITE (10.102) TG.AXIS(I),(P(K,I).K?1.J)
102 FORMAT(A2.8E15.?)
IF(NW.NE.4> Go To 11
9 WHITE (61.103)
103 FORMAT(IHI)
D0 10 I=l.N
101F111TE£61.104) AKIS(I),(P(K.I).K=1.J)

PLOT.

104
11

142

CONT.

FORMAT( 1H .8(3X, E12. 6))
RETURN
END

SUBROUTINE NORM

SUBROUTINE NORM(F,M.NPPS.1CF.SCALE)
COMMON P(7.1024)
DIMENSION F(4.1024)
MLO=ICF-2

MHI=ICF+2

SCALE=0.

DO 1 K=MLO.MHI -
SCALE=SCALE+F(M.K)
SCALE=SCALE/5.

DO 2 K?I.NPPS
F(M.K)=F(M.K)/SCALE
RETURN

END

SUBROUTINE MINN

3

100

4

SUBROUTINE MINN(M.NPPS)
COMMON/SPECT/S(4.1024)
COMMON/CONV/C(4.1024).ERROR(4).SCALC(8)
COMMON/AMP/SCALE(8).ICF(8).RHO.POLEFF
COMMON/SEARCH/XHWDTH.XMSTEP.ISKIP
COMMON P(7.1024)

DIMENSION X1(4),VT(3)

CPOINT=XHWDTH

STEP=XMSTEP

CTST=0.001

NTIMES=I

MORE=0

DO 2 K=1.3

XSTEP=(KF2)*STEP

CALL CONVOLV(K.NPPS.CPOINT.XSTEP.ICF(M),M.ISKIP)
WT(K)=1.

X1(K)=CPOINT¥XSTEP

CALL PARABOL(X1.ERROR.PI,P2.P3)
X1(4)=-P2/(2.*P1)

IFOUR=4

XDIFF=X1(4)-CPOINT

CALL CONVOLV(IFOUR.NPPS.CPOINT.XDIFF.1CF(M),M;ISKIP)
KFLAG=0

ERRM1N=ERROR(4)

DO 3 K=1.3

IF(ERROR(K)-ERRMIN.LE.0) KFLAG=K'
IF(ERROR(K)-ERRMIN.LE.0) ERRMIN=ERRDR(K)
IF(ABS(XDIFF).LT.CTST) KFLAG=4

CONTINUE
STDEV=SQRT(ERROR(4)/FLOAT(NPPS))
WRITE(6I.100) NTIMES.XI(4).STDEV
FORMAT(/40X.SHCYCLE.I3.lSHOF SUBROUTINE MINN.//60X;23HTHE MINIMUM

1HALF-NIDTH=.F10.5/60X.23HTHE STANDARD DEVIATION=.E15.9)

1F(KFLAG.NE.0) GO TO 4
CPOINT=X1(4)

STEP=STEP/2.

NTIMES=NTIMES+1

GO TO 1

IF(MORE.EQ.1.0.KFLAG.EQ.4) GO TO 5

143

MINN. CONT.

101

MORE=1
WRITE (61.101)
FORMAT(//36H PROGRAM IS DIVERGING. TRY'DIFFERENT'STARTTNG PARAMETE

IRS)

CPOINT3XI(KFLAG)

STEP=STEP*2.

NTIMES=NTIMES+1

GO TO I

KALL=1

XDIFF=X1(KFLAG)-CPOINT

CALL CONVOLV(KFLAG.NPPS.CPOINT.XDIFF.ICF(M),MgKALL)
STDEV=SQRT(ERROR(KFLAG)/FLOAT(NPPS))

WRITE (61.102) NTIMES.X1(KFLAG).STDEV

102 FORMAT(//40X.5HAFTER.13.21HCYCLES THE VALUES ARE.//40X;16HBEST’HAL

IF-WIDTH=.F10.5/40X{23HTHE STANDARD DEVIATION=.E15.9)

DO 6 I=1,NPPS
P(1.I)=S(1,I)
P(2.1)=S(M.1)
P(3.I)=C(KFLAG,I)
CALL PLOT(3.NPPS.4)
RETURN

END

SUBROUTINE INTNCOR

0000

1.:

“#6)”

0m“! 01

SUBROUTINE ' Imcom u, NPPS)

CORRECTS SPECTRA ACCORDING TO FORMULA
I(DEPOL,ACTUAL)=1(DEPOL.EXP)/POLEFF-I(POL.EXP)*RHO

COMMON/SPECTVS(4.1024)
COMMON/AMP/SCALE(8).ICF(8).RHO.POLEFF.GAIN(8)
COMMON P(5.1024).D(1024).REP(1024)
RAWDPR=SCALE(M)/SCALE(1)

SCALE(M)=SCALE(M)*POLEFF

IOFFSET=ICF(1)-ICF(ND

ISHIFT=NPPS-IABS(IOFFSET)

IF(IOFFSET.EQ.0) GO TO 7

IF(IOFFSET.LT.0) GO TO 4

DO 1 K?1.ISHIFT
REP(K}IOFFSET)=S(M.K)-RHO*D(K%IOFFSET)*(SCALE(1)/SCALE(M))
DO 2 K=1.IOFFSET

S(M.K)=REP(K}IOFFSET)

DO 3 K=1.ISHIFT

S(M.K+IOFFSET)=REP(K}IOFFSET)

GO TO 9

DO 5 K?1.ISHIFT
S(M.K)=S(M.KFIOFFSET)-RHO*D(K)*(SCALE(1)/SCALE(M))
1UP=ISHIFT+IOFFSET+I

DO 6 K?IUP.ISHIFT

S(M.KPIOFFSET)=S(M.K)

GO TO 9

DO 8 K=1.NPPS
S(M.K)=S(M.K)-RHO*D(K)*(SCALE(1)/SCALE(M))
ICF(M)=ICF(I)

CALL NORM(S.M.NPPS.ICF(M).SCOR)
SCALE(M)=SCALE(M)*SCOR

REALDPR=SCALE(M)/SCALE(1)

WRITE (61.101) RHO.POLEFF,GAIN(M).IOFFSET.RAWDPR.SCALE(M).REALDPR

101 FORMAT(/32H AFTER INTENSITY CORRECTION WITH.T40.21HPOLARIZATION LE
1AKAGE=.F6.4/T41.19HDETECTOR EFFICENCY2.F5.3/T42.léHRECORDER.GAIN=.

2EII.3/T46.14HCENTER OFFSET=.I3/T34.27HCRUDE DEPOLARIZATION RATIO=.
3F7.5.10X.19HTHE SCALING FACTOR=.E13.7/T74.25HTHE DEPOLARIZATION RA
4TIO=.F7.5)

SLOSS=(1.-SCOR)*100.

144

INTNCOR. CONT.

102 FORMAT(///,30H THIS CORRECTION ACCOUNTED FOR. 13.36HPER CENT OF THE
1 TOTAL LINE INTENSITY)

LOSS= IFIX( SLOSS)
WRITE (61.102) LOSS

RETURN
END

SUBROUTI NE CONVOLV

0000

000

SUBROUTINE CONVOLV( M. NPPS . XHWDTH. XCHNGE. ICF , L. ISKIP)

SUBROUTINE CONVOLV CONSTRUCTS A CONVOLUTION OF A LOREN'IZIAN
AND THE POLARIZED LINE. AND MATCHES IT TO A DEPOLARIZED LINE

DIMENS ION WOR( 3000) . XAXISC 3000)
COMMON/SPECT/S( 4 . 1024)
COMMON/CONV/C( 4' . 1024) . ERROR( 4) . SCALC( 8)
COMMON/DATA/AXIS( 1024)

COMMON P( 7 . 1024)

NP'I'1‘=1CF*4+40

JJ=1

DEL-‘- AXIS( 2) -AXIS( 1)
XAXIS(1)=AXIS(I)

NPTTP=NPTT+I

DO 1 K= 1 . NP'I'I'P

XAXIS( K+ 1) =XAXIS( K) +DEL

DO 2 K= l . NPTT

J= ICF*2

XJ=XAXIS( K) -XAXIS( J)

2 WOR( K) = 1 ./(1. +( X.I*XJ)/(XH'WDTH+XCHNGE) *32)

DO 3 K=1.NPPS

3 C(M.K)=0.

13

S IMPSONS RULE INTEGRATION

NS IMPSN=4

NADJ=~2

DO 4- K31 .NPPS. ISKIP

DO 4 N=1.NPPS. ISKIP
KKK=K+2*ICF-N

NS 1 MPSN= NS IMPSN+NADJ
COEFF= FLOAT( NS IMPSN)
NADJ=-NADJ

IF( N. EQ. 1 . O. N. EQ. NPPS) COEFF= 1 .
C( M. K) =C( M. K) +WOR( KKK) *S( JJ .N) *COEFF
NBSLINE=5=RISKIP

IUP= NPPS-4* ISKI P

BLCORR=0.

DO 5 K=1.NBSL1NE. ISKIP
BLCORR= BLCORR+C( M. K)

.00 6 K=IUP.NPPS. ISKIP
BLCORR=BLCORR+C( M. K)
BLCORR= BLCORR/ 10 .

DO 7 K: 1. NPPS. ISKIP

C( M. K) =C( M. K) -BLCORR
YMAX=C(M. I)

DO 8 K= 1 .NPPS. ISKIP
IF(C(M.IO.LE.YMAX) GO TO 8
YMAX=C( M.K)

IRCENT=K

CONTINUE

IDIFF= IRCENT-ICF

IDIFF=( IDIFF/ISKIP)*ISKIP
IF( IDIFF)13. 18.14-

DO 15 K=1.NPPS. ISKIP

145

CONVOLV. CONT.

15 P(1.K-IDIFF)=C(M.K)
IAD=IABS(IDIFF)
DO 16 K=I.IAD.ISKIP

16 P(1.K)=P(1.K+IAD)
DO 17 K31.NPPS.ISKIP

I7 C(M.K)=P(I.K)
GO TO 18

14 IOFF=((NPPS-IDIFF)/ISKIP)*ISK1P
DO 19 K=I.IOFF.ISKIP

I9 C(M.K)=C(M.K+IDIFF)
DO 20 K=IOFF.NPPS.ISKIP

20 C(M.K)=C(M.KFIDIFF)

18 IF(ISKIP.EQ.I) GO TO 10
1CENTL=1RCENT52
ICENTH=1RCENT+2
DO 9 K=ICENTL.ICENTH

9 C( M.K)=C(M. IRCENT)
GO TO 11

10 IRCENT=ICF

11 CALL NORM(C.M.NPPS.IRCENT.SCALC(M))
ERROR(M)=0.
DO 12 KF1.NPPS.ISKIP

l2 ERROR(M)=ERROR(M)+(S(L.K)-C(M,IO)*(S(L.K)-C(M.K))
RETURN
END

SUBROUTINE SMOOTH

SUBROUTINE SMOOTH(KK.NPPS)
COMMON/SPECT/S(4.1024)
COMMON PP(7,1024)
DIMENSION P(17)
NPPS=NPPS-16
DO 1 K?1.16
I P(K+1)=S(KK.K)
DO 3 J=1.NPPS
DO 2 K?1.16
2 P(K)=P(K+l)
P(17)=S(KK.J+16)
SUM=43.*P(9)+42.*(P(8)+P(10))+39.*(P(7)+P(11))+34.*(P(6)+P(12))+27
1*(P(5)+P(13))+18.¥(P(4)+P(14))+7.*(P(3)+P(15))-6.*(P(2)+P(16))-21.
2*(P(1)+P(17))
3 S(KK.J)=SUM/323.
L=NPPS
DO 4 K=1.NPPS
S(KK.L+8)=S(KK,L)
4 L=L-1
DO 5 K?l.8
J=NPPS+8+K§1
L=NPPS+K-1
5 S(KK.J)=S(KK.L)
NPPS=NPPS+I6
RETURN
END

SUBROUTINE PARABOL

SUBROUTINE PARABOL(X.V.A.B.C)

COMMON P(7.1024)

DIMENSION X(3).V(3).Y(3).ERROR(3).ERRSQ(3)
NR1TE(61.100)

146

.PARABOL. com.

100

101

102

103
104

FORMAT(1H1.T24.68HSUBROUTINE PARABOL FITS 3 POINTS TO THE' PARABOLI

1C CURVE Y= AX**2+BX+C)

TM1=(X'(1)-X(2))$(V(2)-V(3))
TP12=(X(2)-X(3))*(V( l)-V(2))
ALPHA=-TMI+TMZ

BETA=TMI*( X( I) +X( 2) )-TMZ*( X( 2)+X( 3))
D=-(X(1)-X(2))*(X(2)-X(3))*(X(3)-X(1))
1F(ALPHA.EQ.0.0) ALPHA=1.0E-20
1F(D.EQ.0.0) D=1.0E-20

A=ALPHA/D

B=BETA/D‘

C=V(1)-A*X(1)*X(1)-B*X(1)
WRITE(61.101) A.B.C

FORMAT(///20X. 12HCOEFFICIEN'IS//20X.4HA = .EI3.7/20X.4HB = .E13.7/2

10X. 4H0 = .E13.7)

CHISQ=0.
WRITE( 61 . 102)
FORMAT( /// 10X. 7HRESULTS//15X. 8HVARIABLE. T30 . 14HEXPERIM. VALUE. T45 .

I I2HTHEOR. VALUE. T60. IOHI)IFFERENCE.T73. 13HDIFF. SQUARED)

DO 1 K=1.3

Y(K)=A*X(K)*X(K)+B*X(K)+C

ERROR(K)=Y(K)-V(K)

ERRSQ( K) =ERROR( K) *ERROR( K)

CHISQ= CHISQ+ERRSQ( K)

WRITE(6I. 103) X(K) .V(K) .Y(K) .ERROR(K).ERRSQ(K)
FORMAT(14X.E13.7.T32.E13.7.T46,EI3.7.T59.E13.7.'175.E13.7)
WRITE(61.104) CHISQ

FORMAT(//10X. 26H’1‘OTAL CHI SQUARED VALUE = .E13.7)
RETURN

END

SUBROUTINE BASE

000

0000

200

201

2

SUBROUTINE BASE(N. X. Y,C)
THIS SUBROUTINE FINDS THE BEST STRAIGHT LINE THROUGH N POINTS

COMMON P(7,1024)

DIMENSION X( 1024) .Y( 1024) .C(3)

WRITE(61.200) N

FORMAT (1H1.T10.42HSUBROUTINE BASE FITTING A STRAIGHT LINE T0 ,

1I4. 12H DATA POINTS//)

SX=0.
SY=0.
SX2=0.
SXY=0.

SX=SUMOFALLX. SY=SUMOFALLY. SX2=SUMOFALLX=RX.
SXY '-' SUM OF ALL X$Y

DO 1 I=I.N

SX=SX+X( I)

SY=SY+Y( I)

SXY=SXY+X( I)*Y( 1)

SXZ=SX2+X( I):KX( I)

FN=FLOAT( N)

D'-' FN*SX2-SX*SX

C( 1)=(FN>¢=SXY-SX$SY) /D

C(2) =(SXL’*S‘I-SX*SXY) /D
WRITE(61.201) (NN.C( NN) .NN=I.2)
FORMAT( //10X. I2HCOEFFICIENTS./( T1 1 .*C(*, 12, *) = $.E15.9))
H=0.

DO 2 I=1.N

YC=C(1)*X(1)+C(2)

H=H+(Y( I)-YC)*(Y( I)-YC)

147

BASE. CONT.

STDEV=SQRT(H/(FN-2.))
WRITE(61.202) H.STDEV
202 FORMAT(/4X.26HTOTAL CHI SQUARED VALUE 3 .E15.9//9X.21HSTANDARD DEV
21ATION = .E15.9/)
RETURN
END

APPENDIX E

TEST ROUTINE

A test routine to be input with the switch register on a PDP 8
minicomputer that is designed to troubleshoot the two counters in the

Ramn interface.

148

149

LOW COUNTER,TEST PROGRAM

0200
0201
0202
0203
0204
0205
0206
0207
0210
0211
0212

7300
6601
6606
6602
6604
6612
7300
6617
6605
5204
7402

/CLEAR AC AND LINK
ICLEAR RAMAN COUNTER
/CLEAR LOW OVERFLOW
/START COUNTING
/LATCH COUNTER
/SAMPLE LOW COUNT
/CLEAR.AC AND LINK
/DRIVE INTO AC
/CHECK LON OVERFLOW
/GO TO 204

/HALT

HIGH COUNTER.TEST PROGRAH

0200
0201
0202
0203
0204
0205
0206
0207
0210
0211
0212

7300
6601
6611
6602
6604
6613
7300
6617
6607
5204
7402

/CLEAR AC AND LINK
/CLEAR RAMAN COUNTER
/CLEAR.HIGH OVERFLOW
/START COUNTING
/LATCH COUNTER
/SAHPLE HIGH COUNT
/CLEAR AC AND LINK
/DRIVE INTO AC
/CHECK HIGH OVERFLOW
/GO TO 204

/HALT

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10

J.

11

F‘

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.3

13

E3

14

M.

15

J.

16

17

S.

18

B.

19

20

J.

21

P.

22

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