National Institute of Standards and Technology

Computational Chemistry Comparison and Benchmark DataBase
Release 19	April 2018
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

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IV.C.1. (XIII.D.1.)

Compare vibrational frequencies in CCCBDB for CH₂C(CH₃)CH₃ (1-Propene, 2-methyl-)

HF/CEP-121G*

Frequency in cm^-1

	Calculated			Experimental
Mode Number	Symmetry	Frequency	diff	Symmetry	Frequency	Comment
1	A1	2977	-12	A1	2989
2	A1	2953	12	A1	2941
3	A1	2870	-41	A1	2911
4	A1	1661	-0	A1	1661
5	A1	1475	5	A1	1470
6	A1	1421	5	A1	1416
7	A1	1388	22	A1	1366
8	A1	1057	-7	A1	1064
9	A1	769	-32	A1	801
10	A1	357	-26	A1	383
11	A2	2910	-60	A2	2970
12	A2	1448	-11	A2	1459
13	A2	999	-77	A2	1076
14	A2	687		A2		assignment questionable (listed as 981)
15	A2	154	-39	A2	193
16	B1	2915	-30	B1	2945
17	B1	1465	21	B1	1444
18	B1	1086	7	B1	1079
19	B1	931	41	B1	890
20	B1	420	-9	B1	429
21	B1	196	0	B1	196
22	B2	3051	-35	B2	3086
23	B2	2951	-29	B2	2980
24	B2	2863	-30	B2	2893
25	B2	1461	3	B2	1458
26	B2	1401	20	B2	1381
27	B2	1259	-23	B2	1282
28	B2	953	-90	B2	1043
29	B2	933	-41	B2	974
30	B2	417	-13	B2	430

The calculated vibrational frequencies were scaled by 0.9034

See section XIII.C.3 List or set vibrational scaling factors to change the scale factors used here.
See section III.B.3.c Calculate a vibrational scaling factor for a set of molecules to determine the least squares best scaling factor.
See section III.B.3.b List of vibrational scaling factors and their uncertainties for information on where the above scaling factor is from.