National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 19April 2018
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
VIInput and output files
VIITutorials and Units
VIIILinks to other sites
IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
XIVReaction data
XVEntropy data
XVIBibliographic data
XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities
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IV.C.1. (XIII.D.1.)

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

MP2/3-21G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3091 28 A1 3063  
2 A1 3066 23 A1 3043  
3 A1 1503 -69 A1 1572  
4 A1 1367 -47 A1 1414  
5 A1 1173 -110 A1 1283  
6 A1 1069 -91 A1 1160  
7 A1 983 -80 A1 1063  
8 A1 757 -207 A1 964  
9 A1 654 35 A1 619  
10 A2 942 6 A2 936  
11 A2 907 44 A2 863  
12 A2 717 -34 A2 751  
13 A2 348 -73 A2 421  
14 B1 937   B1   760 reassinged to mode 15
15 B1 732 -28 B1 760 696 questionable
16 B1 363 -7 B1 370  
17 B2 3076 1 B2 3075  
18 B2 3060 17 B2 3043  
19 B2 1468 -97 B2 1565  
20 B2 1382 -62 B2 1444  
21 B2 1234 -5 B2 1239  
22 B2 1042 -10 B2 1052  
23 B2 978 -31 B2 1009  
24 B2 604 -60 B2 664  
The calculated vibrational frequencies were scaled by 0.9545

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.