National Institute of Standards and Technology

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

I	Introduction
II	Experimental data
III	Calculated data
IV	Data comparisons
V	Cost comparisons
VI	Input and output files
VII	Tutorials and Units
VIII	Links to other sites
IX	Feedback
X	Older CCCBDB versions
XII	Geometries
XIII	Vibrations
XIV	Reaction data
XV	Entropy data
XVI	Bibliographic data
XVII	Ion data
XVIII	Bad calculations
XIX	Index of properties
XX	H-bond dimers
XXI	Oddities

---

NIST policy on privacy, security, and accessibility.

---

© 2013 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved.

The National Institute of Standards and Technology (NIST) is an agency of the U.S. Department of Commerce.

Please send questions, comments, corrections, additions and suggestions to cccbdb@nist.gov.

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

Compare vibrational frequencies for two calculations for CH₃OH^- (Methyl alcohol anion)

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'		2552	2566	-13.3	0.995		1.025	1.026	-0.002	0.999		528.65	579.91	-51.26	0.912
2	A'	A'		2461	2527	-65.9	0.974		1.091	1.093	-0.002	0.998		534.65	443.78	90.87	1.205
3	A'	A'		1486	1485	1.1	1.001		1.168	1.158	0.010	1.008		244.52	231.03	13.49	1.058
4	A'	A'		1470	1458	12.6	1.009		1.072	1.081	-0.010	0.991		47.61	76.78	-29.16	0.620
5	A'	A'		1170	1153	17.4	1.015		1.328	1.332	-0.003	0.998		5.28	2.72	2.56	1.939
6	A'	A'		1139	1133	5.8	1.005		6.862	6.741	0.121	1.018		257.74	248.16	9.59	1.039
7	A'	A'		439	624	-184.9	0.704		1.073	1.059	0.014	1.013		356.34	107.07	249.27	3.328
8	A'	A'		291	332	-40.6	0.878		1.159	1.160	-0.001	1.000		6.07	9.92	-3.85	0.612
9	A"	A"		2480	2510	-30.6	0.988		1.093	1.094	-0.001	0.999		624.27	530.12	94.15	1.178
10	A"	A"		1463	1444	18.5	1.013		1.070	1.073	-0.002	0.998		45.22	38.89	6.33	1.163
11	A"	A"		1174	1163	11.0	1.009		1.307	1.302	0.005	1.004		4.52	0.28	4.24	15.903
12	A"	A"		97	71	26.7	1.378		1.055	1.050	0.004	1.004		2.22	4.70	-2.47	0.473
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.