National Institute of Standards and Technology

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

I	Introduction
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III	Calculated data
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V	Cost comparisons
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XVI	Bibliographic data
XVII	Ion data
XVIII	Bad calculations
XIX	Index of properties
XX	H-bond dimers
XXI	Oddities

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

Compare vibrational frequencies for two calculations for NH₂COOH (Carbamic acid)

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'		3673	3593	79.8	1.022		1.066	1.107	-0.041	0.963		136.42	83.54	52.87	1.633
2	A'	A'		3592	3533	58.6	1.017		1.108	1.065	0.044	1.041		89.58	88.19	1.39	1.016
3	A'	A'		3472	3462	10.0	1.003		1.046	1.045	0.001	1.001		74.00	80.64	-6.64	0.918
4	A'	A'		1813	1787	25.8	1.014		8.088	8.168	-0.080	0.990		689.22	468.27	220.94	1.472
5	A'	A'		1606	1560	46.3	1.030		1.300	1.322	-0.021	0.984		165.83	147.98	17.85	1.121
6	A'	A'		1426	1391	35.2	1.025		2.870	2.744	0.126	1.046		189.15	133.74	55.42	1.414
7	A'	A'		1228	1187	41.1	1.035		1.586	1.480	0.107	1.072		228.06	211.00	17.05	1.081
8	A'	A'		1072	1040	32.1	1.031		1.659	1.735	-0.076	0.956		46.16	32.52	13.64	1.419
9	A'	A'		958	917	41.2	1.045		4.246	4.625	-0.380	0.918		20.08	43.42	-23.34	0.462
10	A'	A'		580	550	29.4	1.053		4.432	4.540	-0.108	0.976		49.97	36.87	13.10	1.355
11	A'	A'		479	463	15.9	1.034		2.737	2.718	0.019	1.007		6.49	6.59	-0.10	0.985
12	A"	A"		788	727	61.0	1.084		9.705	8.412	1.293	1.154		86.34	34.76	51.58	2.484
13	A"	A"		568	577	-9.2	0.984		1.048	1.058	-0.010	0.991		74.48	78.38	-3.90	0.950
14	A"	A"		488	466	21.8	1.047		1.108	1.103	0.005	1.005		79.90	67.79	12.11	1.179
15	A"	A"		144i	268i	124.2	0.537		1.226	1.241	-0.015	0.988		330.93	310.24	20.69	1.067
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.