National Institute of Standards and Technology

Computational Chemistry Comparison and Benchmark DataBase
Release 22	May 2022
NIST Standard Reference Database 101

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III.G.7. (XIII.B.3.) (XIII.D.5.)

Compare vibrational frequencies for two calculations for CH₃COCH₂ (Acetonyl radical)

A = HF/6-31G*

B = MP2/6-31G*

scale factors=0.8985, 0.943

	symmetry			frequency (cm-1)					reduced mass (amu)					IR Intensity (km mol-1)
mode number	A	B		A	B	diff.	ratio		A	B	diff.	ratio		A	B	diff.	ratio
1	A'	A'		3100	3175	-75.3	0.976		1.121	1.121	-0.001	0.999		5.32	2.57	2.75	2.071
2	A'	A'		3001	3065	-63.9	0.979		1.053	1.104	-0.051	0.954		7.20	4.64	2.56	1.551
3	A'	A'		2979	3054	-74.5	0.976		1.102	1.051	0.051	1.048		11.09	0.70	10.39	15.819
4	A'	A'		2883	2935	-51.6	0.982		1.039	1.037	0.002	1.002		11.26	0.26	11.00	43.349
5	A'	A'		1462	1985	-522.6	0.737		1.855	11.995	-10.140	0.155		35.82	775.10	-739.28	0.046
6	A'	A'		1457	1442	15.9	1.011		1.058	1.054	0.004	1.004		8.17	11.95	-3.78	0.684
7	A'	A'		1402	1417	-15.3	0.989		1.415	1.226	0.190	1.155		15.61	31.04	-15.43	0.503
8	A'	A'		1383	1360	23.3	1.017		2.053	1.370	0.682	1.498		2.69	47.00	-44.32	0.057
9	A'	A'		1217	1222	-5.3	0.996		2.881	2.683	0.198	1.074		55.22	102.87	-47.65	0.537
10	A'	A'		1033	1039	-5.8	0.994		1.787	1.602	0.185	1.115		1.95	7.03	-5.08	0.277
11	A'	A'		907	866	41.2	1.048		1.607	1.593	0.014	1.009		12.47	14.48	-2.01	0.861
12	A'	A'		796	783	12.3	1.016		3.258	3.440	-0.182	0.947		0.11	1.00	-0.89	0.108
13	A'	A'		505	507	-2.7	0.995		3.595	3.435	0.160	1.047		18.99	16.80	2.19	1.131
14	A'	A'		366	366	0.7	1.002		2.177	2.142	0.035	1.016		2.48	2.04	0.43	1.213
15	A"	A"		2933	3014	-81.1	0.973		1.102	1.101	0.001	1.001		24.16	5.08	19.08	4.757
16	A"	A"		1460	1448	11.9	1.008		1.047	1.050	-0.003	0.997		7.05	10.63	-3.58	0.663
17	A"	A"		1017	1011	6.2	1.006		1.562	1.837	-0.274	0.851		2.84	10.22	-7.38	0.278
18	A"	A"		679	620	58.7	1.095		1.438	1.657	-0.219	0.868		40.11	40.43	-0.32	0.992
19	A"	A"		489	498	-8.6	0.983		2.324	1.604	0.720	1.449		0.09	4.27	-4.18	0.020
20	A"	A"		407	252	155.1	1.617		1.043	1.042	0.001	1.001		0.34	0.00	0.34	568.833
21	A"	A"		60	97	-37.5	0.614		1.069	1.074	-0.004	0.996		0.06	0.00	0.06	31.944
scaled by				0.8985	0.943

See section III.C.1 List or set vibrational scaling factors to change the scale factors used here.
See section III.C.2 Calculate a vibrational scaling factor for a given set of molecules to determine the least squares best scaling factor.