National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 18October 2016
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
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XVIIIon data
XVIIIBad calculations
XIXIndex of properties
XXH-bond dimers
XXIOddities

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

Compare vibrational frequencies for two calculations for CH3 (Methyl 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 A1' A1'   2951 3039 -87.9 0.971     1.008       0.00 0.00 0.00  
2 A2" A2"   277 376 -98.9 0.737     1.236       83.24 94.03 -10.79 0.885
3 E' E'   3110 3217 -107.2 0.967     1.119       11.66 4.21 7.45 2.769
4 E' E'   3110 3217 -107.2 0.967     1.119       11.66 4.21 7.45 2.769
5 E' E'   1384 1396 -12.1 0.991     1.102       0.55 2.37 -1.82 0.233
6 E' E'   1384 1396 -12.1 0.991     1.102       0.55 2.37 -1.82 0.233
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.