III.B.3.b. (XIII.C.2.)

Vibrational frequency scaling factors

Calculated vibrational frequencies ("theory" in table) are calculated at CISD/3-21G*

Scale factor	How many		Source
	Molecules	Vibrations
0.934 ± 0.026	9	141	cccbdb

Jump to histogram

Formula	Name	Mode	Symmetry	Frequency			Count
				Theory	Experiment	ratio	molecules	vibrations
CH3CH2NH2	Ethylamine	1	A'	3466	3345	0.965	1	1
		2	A'	3155	2985	0.946	1	2
		3	A'	3110	2840	0.913	1	3
		4	A'	3086	2860	0.927	1	4
		5	A'	1780	1622	0.911	1	5
		6	A'	1608	1487	0.925	1	6
		7	A'	1592	1465	0.920	1	7
		8	A'	1498	1378	0.920	1	8
		9	A'	1442	1397	0.969	1	9
		10	A'	1193	1016	0.851	1	10
		11	A'	1048	1086	1.037	1	11
		12	A'	914	892	0.975	1	12
		13	A'	808	773	0.957	1	13
		14	A'	403	403	1.000	1	14
		15	A"	3557	3412	0.959	1	15
		16	A"	3161	2924	0.925	1	16
		17	A"	3135	2906	0.927	1	17
		18	A"	1605	1455	0.907	1	18
		19	A"	1445	1238	0.857	1	19
		20	A"	1343	1293	0.963	1	20
		21	A"	1053	1117	1.061	1	21
		22	A"	807	816	1.011	1	22
		23	A"	316	259	0.821	1	23
		24	A"	262	218	0.831	1	24
CH3COOCH3	methyl acetate	1	A'	3250	3035	0.934	2	25
		2	A'	3249	3031	0.933	2	26
		3	A'	3150	2966	0.941	2	27
		4	A'	3146	2964	0.942	2	28
		5	A'	1844	1771	0.960	2	29
		6	A'	1623	1460	0.899	2	30
		7	A'	1588	1440	0.907	2	31
		8	A'	1557	1430	0.919	2	32
		9	A'	1503	1375	0.915	2	33
		10	A'	1314	1248	0.950	2	34
		11	A'	1243	1159	0.933	2	35
		12	A'	1125	1060	0.942	2	36
		13	A'	1015	980	0.966	2	37
		14	A'	850	844	0.993	2	38
		15	A'	654	639	0.977	2	39
		16	A'	418	429	1.027	2	40
		17	A'	276	303	1.099	2	41
		18	A"	3212	3005	0.935	2	42
		19	A"	3210	2994	0.933	2	43
		20	A"	1608	1460	0.908	2	44
		21	A"	1596	1430	0.896	2	45
		22	A"	1220	1187	0.973	2	46
		23	A"	1151	1036	0.900	2	47
		24	A"	618	607	0.982	2	48
		25	A"	174	187	1.073	2	49
		26	A"	116	136	1.177	2	50
		27	A"	105	110	1.048	2	51
CH2CHCH3	Propene	1	A'	3263	3090	0.947	3	52
		2	A'	3195	3013	0.943	3	53
		3	A'	3181	2991	0.940	3	54
		4	A'	3152	2954	0.937	3	55
		5	A'	3084	2871	0.931	3	56
		6	A'	1754	1650	0.941	3	57
		7	A'	1604	1470	0.916	3	58
		8	A'	1542	1420	0.921	3	59
		9	A'	1507	1378	0.915	3	60
		10	A'	1401	1297	0.926	3	61
		11	A'	1248	1171	0.938	3	62
		12	A'	1019	963	0.945	3	63
		13	A'	917	920	1.003	3	64
		14	A'	449	428	0.954	3	65
		15	A"	3135	2954	0.942	3	66
		16	A"	1591	1443	0.907	3	67
		17	A"	1146	1045	0.912	3	68
		18	A"	1064	991	0.931	3	69
		19	A"	994	912	0.918	3	70
		20	A"	607	578	0.952	3	71
		21	A"	187	174	0.928	3	72
CH3CH2CHO	Propanal	1	A'	3193	2981	0.934	4	73
		2	A'	3128	2904	0.928	4	74
		3	A'	3105	2895	0.933	4	75
		4	A'	3017	2809	0.931	4	76
		5	A'	1782	1743	0.978	4	77
		6	A'	1611	1460	0.906	4	78
		7	A'	1572	1416	0.901	4	79
		8	A'	1523	1390	0.912	4	80
		9	A'	1493	1376	0.922	4	81
		10	A'	1420	1335	0.940	4	82
		11	A'	1153	1093	0.948	4	83
		12	A'	1041	993	0.954	4	84
		13	A'	861	848	0.985	4	85
		14	A'	702	668	0.952	4	86
		15	A'	280	271	0.966	4	87
		16	A"	3197	2992	0.936	4	88
		17	A"	3133	2942	0.939	4	89
		18	A"	1613	1451	0.900	4	90
		19	A"	1365	1250	0.916	4	91
		20	A"	1220	1118	0.916	4	92
		21	A"	967	892	0.923	4	93
		22	A"	737	660	0.895	4	94
		23	A"	240	220	0.917	4	95
		24	A"	135	135	1.000	4	96
C5H8	1,4-Pentadiene	1	A	3289	3080	0.936	5	97
		2	A	3223	3012	0.934	5	98
		3	A	3207	3012	0.939	5	99
		4	A	3102	2900	0.935	5	100
		5	A	1776	1644	0.926	5	101
		6	A	1584	1433	0.905	5	102
		7	A	1558	1413	0.907	5	103
		8	A	1403	1295	0.923	5	104
		9	A	1341	1263	0.942	5	105
		10	A	1150	1120	0.974	5	106
		11	A	1080	995	0.921	5	107
		12	A	1020	918	0.900	5	108
		13	A	949	876	0.923	5	109
		14	A	703	562	0.800	5	110
		15	A	392	421	1.075	5	111
		16	A	318	137	0.430	5	112
		17	A	86	102	1.190	5	113
		18	B	3289	3080	0.936	5	114
		19	B	3222	3012	0.935	5	115
		20	B	3207	3012	0.939	5	116
		21	B	3143	2982	0.949	5	117
		22	B	1760	1640	0.932	5	118
		23	B	1553	1413	0.910	5	119
		24	B	1405	1314	0.935	5	120
		25	B	1393	1280	0.919	5	121
		26	B	1227	1060	0.864	5	122
		27	B	1081	995	0.920	5	123
		28	B	1019	995	0.976	5	124
		29	B	985	920	0.934	5	125
		30	B	945	760	0.804	5	126
		31	B	637	721	1.132	5	127
		32	B	474	421	0.888	5	128
		33	B	90	331	3.663	5	129
CS	carbon monosulfide	1	Σ	1329	1285	0.967	6	130
SiH2Cl2	dichlorosilane	1	A1	2406	2224	0.924	7	131
		2	A1	1009	954	0.946	7	132
		3	A1	558	527	0.944	7	133
		4	A1	200	188	0.941	7	134
		5	A2	770	710	0.922	7	135
		6	B1	2418	2237	0.925	7	136
		7	B1	630	602	0.955	7	137
		8	B2	947	876	0.925	7	138
		9	B2	628	590	0.939	7	139
LiO	lithium oxide	1	Σ	892	815	0.913	8	140
NaO	sodium monoxide	1	Σ	539	492	0.914	9	141

How do we calculate the scaling factor?

Histogram of vibrational frequency ratios

Ratios greater than 1.35 are in the 1.35 bin. Ratios less than 0.7 are in the 0.7 bin.

	70
	60
	50
	40
	30
	20
	10
	0
		0.70			0.75			0.80			0.85			0.90			0.95			1.00			1.05			1.10			1.15			1.20			1.25			1.30			1.35
Ratio of experimental frequency to calculated frequency