JOURNAL
OF MOLECULAR
SPECTROSCOPY
84,342-354
The Infrared
(1980)
Band v6 of CD31
M. KOIVUSAARI, J. KAUPPINEN, A-M. KELHALA, AND R. ANTTILA Department
of Physics.
University of Oulu, SF-90570
Oulu 57, Finland
The lowest perpendicular fundamental Yeof CD,1 around 650 cm-’ is studied at a resolution of 0.015 cm-‘. More than 2000 rotational transitions are identified and they are used to get the molecular constants of the level v6 = 1, including, e.g., the 7 constants.
INTRODUCTION
A few years ago Anderson and Overend (I ) recorded the perpendicular fundamental band vg of CDJ with a resolution of about 0.03 cm-l. Using the interferograms which we registered for the lowest fundamental y3 (2), we could compute the spectrum in the region of vg, also. Since the present resolution is improved by a factor of two as compared to the previous measurements it has been possible to observe the J structure in the Q branches of the subbands. We also extended the assignments to higher J and K values than those given in Ref. (1). SPECTRUM AND RESULTS
The experimental conditions are given in Ref. (2). To illustrate the spectra used for the analysis, some examples are given. In Fig. 1 the Q branches “Q,, and “Qz are presented. The J structure begins to be resolved from about J = 25 onwards. Due to the I-type doubling, “QOappears slightly sharper than the other Q branches. This is discernible in Fig. 1, although the difference is not very striking. In Fig. 2 a small region of the upper part of the band is given together with the assignments. In the spectrum we identified about 2200 rotational transitions in vg. Several lines which proved to be strongly blended and shifted were omitted from the final fits. The lines used are listed in Table I. For the vibrational ground state the term values F(J,K)
= B,J(J
+ 1) + (A,, - B,,)K2 - D&W
+ 1)’
- D$PJ(J
+ 1) - D;K”
(1)
were applied. All the constants in Eq. (1) were fixed and this data set is presented at the beginning of Table II. We tried to determine the distortion constants 0; and 06 from ground-state combination differences using P, Q, and R lines and the constrained B,, value. The results from 602 differences were 0; = 1.250(7) x lop7
0022-2852/80/120342-13$02.00/O Copyright
0 1980 by Academic
All rights of reproduction
Press, Inc.
in any form reserved.
342
343
ue BAND OF CD,1
663
664
665 I
666
FIG. 1. The Q branches RQ,,and “Q2 in the fundamental band v6of CDJ. Owing to the l-type doubling HQ,,is narrower than the other Q branches. The experimental conditions were: absorption length 3 m, pressure 500 Pa (3.7 Torr), room temperature.
cm-’ andDiK = 1.620(42) x lo+ cm-l. The former of these confirms the result from the parallel band v3 (2), but has slightly wider error limits. The value ofDiKK,on the other hand, agrees with the microwave result (3), but the uncertainty is more than tenfold. Thus no ground-state constants from this work were used in the further analysis. The term values for the upper vibrational state v6 = 1 were calculated according to the expression (lk 1 = K) F’(.f,k,l)
= v6 + &J(./
+ 1) + (A, - &)k* - 2(A5)&&
- D&I*(.I + l)* - D$V.J(J
+ 1) - Dfk” + qgkl,J(J + 1) + $k31,.
(2)
When the observed lines were being fitted, they were corrected by ground-state contributions as in Ref. (5). Thus the output consisted of the band center, the changes of the rotational and centrifugal distortion constants due to the vibrational excitation, andA{ together with the 7 constants. The lines belonging to the subband K = 1 + K = 0 were not included in the general fit because of the l-type doubling. The results are compiled in Table II. Our at is in very good agreement with the microwave result 0.4902(13) x 10m3cm-’ of Kuczkowski (6). Even our value for q1 compares well with that given in Ref. (6).
344
KOIVUSAARI
ET AL.
692
633
694
EYi
636
636
637
690
633
7cIo I
701
702
703
704
700 I
FIG. 2. A small region in the R part of the y6 band of CD,1 to illustrate the quality of the spectra. The resolution is 0.015 cm-‘. The experimental conditions are given in the caption of Fig. 1.
Owing to the I-type doubling an additional term ?(1/2)q,J(J + 1) must be added to F’(J,k,l) in Eq. (2) when k = 1, = + 1. The energy levels are then doublets, so that the “Q,,(J) lines reach the upper components, whereas the RR0(J) and RPO(J) transitions lead to the lower component levels of the doublets. According to the sign convention of Cartwright and Mills (7) qs is then negative. In the analysis of the subband KAK = 0 to get the numerical value of qs we constrained all the constants to their previous values, letting qs be the only variable. In the
1
Nore.
231
.28 *cc
-15 -0‘ 1C6 -1, .,o
-04
to2 -14
-I5
S56.95?6 656.0222
656.aLSe 656.8127 656.7759 656.7350 CSb.bP75
556.‘116
65b.3‘79 656.2Ps8
S5~.20,2
The differences
.r’C .O2 .,l +ce l,, .,P .O9 ttl -01 +2c -2c
E57.3072 657.2620 657.2576 657.2311 657.206‘ t57.1713 657.147, 657.,,P, C57.0eb7 657.058> 657.D2,L
IhX = 0
+33
.J5 +te l LR +1c
,bi.J?DB
663.213, bb’j.2‘40 6bC.lJ25 b5C.1353
obs. -talc.
.C‘ -38 l ,3 l J6 +I9 .,e
11: l 3b .I‘ -32 +5c ‘3C 114 .,C +5c +32
bbl.,LP1 66,.,198 ,6,.O?lC ,bl.3557 661.3324 ,bC.P3LP 660.1527 660.9218 665.8963 660.S530
563.,‘?6 660.6979 6bG.6536 660.6,er. 660.5752 66L.523,
*2x 115
!
(cm-‘)
are given
652.2643 652.2363 652.1557
652.3599
663.56‘?
663.3596
66L.SSZP 65L.0071
666.2137 66‘.1578
bbG.k'PJ7 bbl.953, 55‘.3199 6b‘.SBIZ 6,‘.9535 bbL.BlSl 66&.77,9 LLI.,LlD 66‘.7056 66‘.,573 66‘.52,5 bLC.5836 bbL.536, 66b.bPSO 6,‘.‘521 664.1052
655.1573 665.1232
l ,L
l 28
-‘I .3L
+I5 -J7
-06 l c1. -10 -cle .,9 ‘00 -2‘ -37 125 -56 -22 .i‘ -2‘ l 10 l ,3 *I5
l 37 l 03
LAI = 2
-16 -72
-3b
66a.53‘9 6‘8.‘28, 6‘5.,,78
-15 -22 -‘I +,L +,2
-25
-07 -13 +a,
-3, -36
1L.3.33,6 S&E.7339 b‘E.73‘1 668.670! 6kP.6‘07
6‘8.92,s
blP.21,7 b‘P.ZIDD t&9.,77&
b&9.,537 649.3159
tl3 l 36 -33 -03 -16 l II3 -53
663.066~
,CS.i,‘4 565.1624
563.306’
,69.&3,2
66~.003‘ 563.9677 569.9366 665.9083 669.8729 5c3.es71 569.!033 669.7669 668.7313 66?i.698k 569.6573 569.blPb 663.5739
+64
.23 lc,
10,
+I9
l 55 -c, -Cb l 2’ +01 -17 -C7 -1‘ +c3 .I87 l2B r&k -05
6‘1.3512 644.9283 644.776) 6GL.7271
bCL.775L
117 -,7 -26 132
-35
l ,, 13, -32 l 02
6‘5.2‘2, 645.1993 bLS.1571
-37
-90
-02 .DJ -35 -13 .DS to2 -09 196 -9‘
6‘5.323~
6,5.,35?
bL5.‘7,6
645.9282 bLS.SC‘S 6‘5.778, 645.751, 6‘5.726, 6‘5.6975 6C5.6673 645.5383 6‘5.5064
LrAI:= -3
v6 of CDJ
-03 -30 -45 -66
K&K= 3
Band
569.3251 56?.JCbI ,61.290, 569.2712
Fundamental
KAX= -z
6‘9.6662 6‘9.6‘26 6‘9.6170 6‘9.5316 6‘9.56‘0 6LP.5387 6‘9.?367
in the Perpendicular
I
in the units of IO-” cm-‘.
-35 -61 -37
-‘I
-39 -53
652.6582 652.62CC
-36 -22 -12 -51 -51 -11
65J.12‘7 653.0367 b53.DSO5 65J.OJBI 652.971, 652.P32P -52
131 -LO
653.2605 65J.224J
652.8&&L
l 37 -00 -51
t1, -3‘ -51 -6,
653.3506 653.3514 653.3169
6,,.6,89 613.6211
653.6563
65,.675?
KM = -1
Line Positions
CC,.JOOP 561.277‘
KbK =
Observed
TABLE
671.9?3&
671.1912
67Z.,‘S3
672.JILS 672.2S57
672.5,21
672.7450 672.705, b72*6?3b
b72.1211 b72.8850 672.95‘6
672.9759
673.1‘,9 673.1124 673.0893 673.3623 673.0319
-28
.,8
.,P
.,J 134
.I0
-25 -15 l cl8
.L2 -02 ‘22
-10
.I, -3, l 21 .J5 -09
lb* = c
R
w
: 3
0
LO
bl 62 63 64 65 bb
5
-37 -27 l01 -35
673.6095
679.306
579.9b39
be3.0735
633.17‘5
b93.3225 b93.2737
631.4blP 653.4156
651.505
693.5328
650.7742
695.8232
683.?570 bS0.9257
bSl.5757
-44
-c3
t23
+39
110
*IO *OS
+05
l14
-13
414
134
lOE
-co *CS
101
*33.,439
t33.3163
633.4729
$33.5754
b33.9415 633.9990 633.8564 633.E133 b33.7b42 633.7179
634.0239
634.3721 b34.3481 634.3127 634.2779 634.2451 b34.2114 b34.1777 634.lJP9
634.4b40 634.4323
634.5352 634.5657 634.5371
-21
+21
-05
135
101 l09 l09 +21 -lb -76
lzs
-25 l4Z l05 -14 -05 l3J 122 l13
t27 -70
-11 l2‘ -23
bP3.6667
5S4.0722
5P4.1513
5e4.4714 604.4254 be4.3779
be4.6045 604.5634
5e4.34ov 5YL.6059 be4.7591 6e4.7262
5P4.9941 584.9523 6?4.9lbJ
5!5.21., 5eS.1865 bP5.lb32 bP3.1364 583.1085
bE3.2849
-31 -19
637.2964 637.2441 637.19Yb b37.1425
-36
.12
637.4901 637.3943
.I9 -14 -13 -14 139
-24
+I6 -05
+26
.i; 437 -41 -31
+32 -28
637.7482 b37.7351 637.6636 637.5209 637.5790
637.9233
637.9710 637.9350
630.0397
638.1595 63S.1305 63S.CP57 6?9.0687
. .._ _.
63Y.214C 638.1959
$29 -01 -11 -21
:
.27
675.9323 675.0752
-23
-34 +07
l35
-29 l17 -31 135
,7,.3‘26
67,.2402
575.42Yb b76.3947
576.5791
U;.;;;' . 676.7896 6?6.7546
l2S
575.957c 676.9243 +33
+2c +36 -18
577.0711 57?.F!426 677.0121
631.204D b91.177P b91.1527 681.1256
5e3.4709 5e3.4153
*I7 -09 -10 -0, .48
-1C
b41.1936
041.1032 b41.@479 6‘C.9973 640.9467 bLO.evPZ
.36 -lb *OS -C, 112 -17
t30 -07 -28 131 to9 +CO 1Cb tC2 to6 -39
641.5438 641.4997 641.4635 bL1.4178 641.3755 641.3298
6‘1.9978 641.PblP 6L1.9JYI 641.9166 tL1.8bS3 641.6544 64Y.B2!9 641.7916 641.7590 641.7205
-12 130
677.1428 577.1231
I-Continued
3" 3 3
i
D
57 5s 59
ii
: 3 3 i
3 0 0 3 J
3
: 3 I
3 3
; :
i
i 3 3
3
50 49 5, 52 53 54 55
39 LO ‘1 42 ‘3 44 45 4b 47 49
22 23 24 25 26 27 29 29 30 31 32 33 34 35 36 37 38
TABLE
630.5155
.27
-‘8 to‘
-13
l02
l3,
-07 -03 -0,
-09 l13
-3? -14 too -14
629.1J825
630.1192 630.1733 630.3255
635.2435 633.2059
633.4058
b30.5514 630.5137 b30.4S19
633.6497
-03
.Gl
639.7392
630.9195
llJ
-20 +OS +12 ‘lb
l‘S
l01
+,b l05 -07
-34 193
-03
a07 -23 *,3
-02
l12
tl5
r,3
697.6111
bBB.0331 687.9893
688.2035
696.3613
688.504b b96.4592
6.36.5995
696.7309
688.5917 688.9553 6ld.9151
689.JOl5 6B8.9b47
bBV.3738
6EV.2450 619.2222 6S9.192S 68V.1641 5S9.1327
b8V.3495 b89.3292
‘12
-43 l23
-3‘
-29
-37 -14
-10
-04
to3 +24 *I7
-02 -06
l22
-17 llY $37 113 633
+26 l5b
ZJ‘)o-
?LS“ZLP 8C91’219
EC66’~OL
52SO’LOL 65SO’SOL 2SS“SOL 22BL’SOL
‘S92’SOL
2bbS’SOL CCS~‘SOL 9?L?.EOL Ei‘S’SOL
PCZF’SOL SSS9’COL
e‘2L’to‘
L‘SL’SOL StoL’saL SCL6’SOL 67CS’SllL 0996’5OL
,!Z-
IIvcSC17*
Ls-
OC+ oc* Lcvat
LCSC.
6‘.
LC* ‘c* 1‘4 ‘9,c+
f ‘01’9‘9 CLSL*F‘P
L96L’C‘P ZV22’FLP
L‘‘1.
5cSC-
00.
9e26-stv 6LFt’SlP
ro66’s‘P
S2+
oo-
1c* SCto*
901
fLFL.
SOSi’b‘P Lf66’6‘9 00‘6’6‘P
60CE'6‘P
et27*6t9 2PS?‘6‘I
22SC-
oc+
,S,s*L69 stPs*L(IC
2CZS’lbP
CBLB’LZP ~658~229 L6,b’ZZP
kc.
~269’22P ?OSL’22P
LIcr*zZP
L‘II-
LCOL.
SC’
?btL’?b‘
9118’265 EOi6*76C 6:2c’2t.o
ossL’:ds S‘. ‘7.
czVI,,-
28 29 JO
:: ** 2,
1
:
:
1
-1c
1 1 1
-04
-2, l 20 .OP -56 -5c
-07 -0, .52
.32
6,5.26?,
676.6427 t.,6.P876 671.1211 b,,.Ll,, 6,,.PP11
*,P.ooJ? tBIP.3321 679.6692
680.3225
.10 -‘3 l 3e .CS -16 .52 -04 -I, .O,
.‘O -C? 610 *PO -1, .07
l 25
.‘i
-0, -10 .3, .25
-06
1
:
:
: .:
:: ::
16 17 18 19 20 21 22 23
:
-07 -39 l I* -24 -II
-32
1
9 10 ,1
bbZ.,PZb
.50 .OP
i
1
I
-67 -08
b
:
1 1
5 6
3
&
.,P
.5C
582.‘565
-53 -21 .51
-3‘ -51 “2 .36 -11 -16 12‘ -39 -08
-16 .01 -1‘ -24 -11 105 .18 -28 +27 -50 .,t -72 -25 -39 -17 .25
681.0757
,,P.,b32 680.0234 580.1506
515.73E6 L76.0973 6,6.‘689 6,,.11265 ,,,.,81, 577.5133 577.9010 5,8.2SBJ 518.5139
,6P.31‘5 b6P.7780 670.1570 s70.5555 ,70.9153 67,.2-+LI ,?I.6721 672.0‘26 bl2.4219 b,2.,8,8 6,1.1,91 6,,.5257 S,J.PO,, 571.2737 L,‘.,‘G? 675.0116
t52 -IS *22 -25 -15 -58 -27 .62 l 53
.‘P .08
d70.8‘P‘ 611.2006 ~71,555,
-17 -IL -39
-50 l 00 -2s
.oo
.O‘
.59 -21 -37
.JO
.‘2 -25
136
+Db .,S
-02
-'3c .‘9 -31
*Jo -07 -16 -33 -26 -05 .21 -68 -10 -09 -52
.i?
l n,
.GO
.05 -17 -59
.,L
-09 .,P '08 -06 -09 .GP
l ‘o
.6&
.O,
‘6‘
-11
-09 .2I .29 .>8 -79 -27 -18 -36 -‘2
430 t7-s .Ol -40 .06 l 09 .26
.ii
.c7
‘01
-10
.“
.11
-02
-22
*2t +02
l 05 l 22 -06
.‘I
-55 -32
-00
.08
.OP
.LP -‘J -7,
-01
-07 .04
*so
-30
*or
-57 +ll
-ii
.,I
t‘6
-1z
-64 .I,
l 27
.08
-32 109
430 l 56
-08
l 71
-0‘ -02 -40
PJflu!WQ-I
TI8VL
co-
LO.
cc* P,“‘OZI Lcco’o*~ ,,69.6LL :
:
*c
cc
SC 1c 9‘
::
v,
cc
:: LC 9c
09
-1
1:
r:
1:
I:
-1 -1 -1 -, -1 -1
1: 1:
-1 -1
1:
1: 1:
-1
-1
-1
1:
-1 -1 -1
1:
-1 -1 _,
-1
-1 -1
1:
1:
-1
r:
-1
1:
r:
TABLE
I -Continued
,f,.,ZPl
-36
TABLE
I-Continued
50 51
48 L?
32 33 3L
JO 31
is 26 27 28 2?
-1 -1 -1 -7 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -1 -, -1 -1 -1 -1 -1 -1 -1 -t -1 -1 -1 -1 -1 -1 -1 -1 -1 -7 -7 -1 -1 -1 -9 -1 -1 -1
-11 112 .lL -25 100 .C‘ l29 117 -&I -‘b +05 .I, -15 405 .Ol 108 -18 -22 +(I 151 loo -20 -03 .P, +17 -10 10& -1, -0I
-01 a09 .O, l03 -39 too to9
+57
515.1TJ1 615.7635 515.3538 61&.9,31 514.5210 61‘.1051 513.5918 613.2732 512.@436 512.62?2 612.0,“ 511.59AO 611.169‘ blO.7LB.S LlO.JZC7 609.9009 609.1728 509.0151 508.5228 508.199‘ bEI.Ib‘L 507.3325 505.9037 606.L730 505.0L21 505.5051 505.1736 bOb.7372 501.3022
503.&295 502.9915 502.5515 502.1119 501.5b59 501.22?4 bOO.78?0
599.9055
-JO .OC *I& -15 -16 lo‘ -5‘ +D2 -12 *lb lrJ9 .I8 129 '33 l08 .I6 -22 lcl6 -,8
.,I -23 +,B
~07.1738 LCS.75OL $05.3276
[email protected] bOS.4730 5(r5.0&81 b06.6153 604.1913 505.7503 bOJ.332I 602.9308 502.4595 602.0377 5C1.5312 501.1571 LDC.7324 ~CO.IP&l 599.8571 599.418,
59e.1353 597.55b5 597.2206
-,1 l09 156
-18
507.59Lb
5?5.S7?2 59S.4‘09 59‘.???&
-31 -33 l33 -co -I)1 -57 +,5 .05 +39 +32 -04
~li.13~3 611.7731 611.353‘ b1C.9‘1~ 510.529.S 610.1128 4@?.5?78 50?.27Bb SOP.9530 5OB.4393 SOE.0178
5?2.33I?
639.2285 537.0lL9 537.4303 636.9341 bJb.5588 635.1528 bO5.7346 bzl5.3115 604.89‘9 634.4762 b3L.0525 533.5302 5~3.2355 502.7325 532.3585 631.?32? 531.5061 531.0753 530.5~85 530.2179 5??.79?? 5cJV.3585 598.9271 519.L.92, 533.0593 5?7.62&? 517.1319 516.7596 5?6.3217 5?5.8?92 535.LLOP 5?&*???‘ 5?‘.55&7 5?‘.1172 5?3.590& 5?,.232L -7,
-91 -32 -35 -03 -3, +lO l,, -31 -,o .I? -31 433 -33 -90 .3? tl, +01 -37 l02 -11 +J? 413 .,J -OS -33 .OD .22 .5? +I2 435 .O? -10 -55 -15 l32 -23 595.S419 575.4162
595.27?7
59P.5942 599.2532 599.943, 5PS.6203 597.9913 5?7.555& 597.1352 5?5.70?~
5')~.3022 505.9810 503.1711 503.3562 502.6399 602.2235 bO1.5035 601.3892 504.?53! 500.5,?5 .Ol -18 -17 llO *lb +02 -05 118 l22 -46 -t5
113 -54 -01 -39 l08 +35 -DS -14 -07 -00
TABLE
l06 411 +lb +Ol .O? 113 to2 l33 -22 45‘ 425 -01
517.47?6 5?7.3587 5?5.5370 535.2124 5?5.79?3 595.3550 5)4.5117 5?4.0&72 5?3.5537 5?,.2,2L 5?2.7??6 572.3561
loo
-07 -06 -03 l39 -0
l05
530.L0b1 599.397~ 5?9.57?5 599.1553 518.7371 5?I.JI?b 5?7.8979
I-Conrinued
5e2.3595
-00
+23 -58
-53 405 +21 l56 +33 .22 +25
5P9.,42, 5e9.9177 5e3.k082 5e9.0591 se7.5239 587.1889 5e5.7364
5eJ.bBBl 5@,.237?
102 -18 -16 -22 -15 -02 -20 +26 -22 .I1 -29 l27 105 -0B -30
lo,
595.53bL 591.12Gb 595.7015 595.2841 59b.8653 3?4*4b53 594.0273 593.6044 593.1870 592.7593 592.3389 591.9102 5?l.L?05 591.0519 lQ3.5334 593.2032 587.2157 586.7932 585.3557 555.9295 585.bPPS 595.0163 SSl..L,CZ 59‘.2075
599.7582 589.342, 58B.9177 585.4882
592.5987 592.2748 59l*lb7? 5?l.L523 591.0289 590.5095
tO2 155 -32 -00 l07 -16 -lb lb5
+,b +OI -05 -5b
-35 -70 r27 +55 rll 120
-31 101 -13 -58 '27 '23
584.675‘ 581.2479 593.JJJ7 503.&027
*I7 -90 -27 -‘L
-I8
505.9503 585.5302
588.3392 507.5f?S 507.2157 505.7932
588.9912
582.5929 582.1713 581.7510 581.3289 580.8997 580.4595 50O.Ob51
58L.279‘ 583.6507 583.4627
5.85.110
-33 -17 .I9 +LB +o -21 l25
-11 -00 l25
-28
354
KOIVUSAARI TABLE
ET AL. II
Results from the Analysis of the Perpendicular
Band Yeof CDJ
Constrained ground state constants:
*0 *0
[cm-']
= 0.2014825
131
D;I
[lO-7 cm-' ]
=
1.244
[2]
[cm-‘]
=
[41
DJoK
[lo-6 cm-' I
=
1.611
[31
1); [lo-' cm-' ]
=
2.26
[4]
2.59356
Results from the fit: [cm-']
=
[lo-3 an-' I
=
-0.49049(23)
-3 cm-‘1 [IO
=
[lo-3 cm-'] [cm-']
"0
B6-Bo As-Ao-(B6-Bo)
*6-*0 (A<),
656.'692(2)
=
0.41(6)
DJK_DJK 6 o [lo-g m-‘I
=
8.5(12)
14.0553(29)
D;-D;
[1o-6 cm-']
=
0.5&9(9)
=
13.5649(32)
n;i
[ 10-6 cm-‘] =
=
0.463451('0)
D;-D;
ail-‘1
['o-4 cm-']
'lgK
Number of lines 1966, standard deviation 0.0026 cm
[lo-'
=
1.476(11)
0.4296(lo)
-1
Result from the subband KAK = 0: [lo-j cm-' I
q6
=
-0.13916(28)
aThe error limits are standard deviations in the units of the last digit given.
calculation we used 22 Q lines and 88 R orP lines. The fit, with a standard deviation of 0.0025 cm-l, led to the result shown at the bottom of Table II. It is near to the value in Ref. (6), but has slightly smaller error limits. RECEIVED:
October 5, 1979 REFERENCES
1. D. R. ANDERSON AND J. OVEREND, Spectrochim. Acta A 28, 1231- 1251 (1972). 2. R. ANTTILA, M. KOIVUSAARI,J. KAUPPINEN, E. KYR~, AND F. HEGELUND, J. Mol. Spectrosc. 84,225-233
(1980).
3. A. K. GARRISON,J. W. SIMMONS, AND C. ALEXANDER,J. Chem.
Phys. 45, 413-415 (1966). 4. H. MATSUURA AND T. SHIMANOUCHI,J. Mol. Spectrosc. 60, 93- 110 (1976). 5. F. HEGELUND, R. ANTTILA, AND J. KAUPPINEN, J. Mol. Spectrosc. 81, 164-178 (1980). 6. R. L. KUCZKOWSKI,J. Mol. Spectrosc. 45, 261-270 (1973). 7. G. J. CARTWRIGHTAND I. M. MILLS, J. MO/. Spectrosc. 34, 415-439
(1970).