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
XVIBibliographic data
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 N2O (Nitrous oxide)

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 Σ Σ   2366 2119 247.2 1.117   14.032 14.286 -0.254 0.982   490.12 263.36 226.77 1.861
2 Σ Σ   1252 1215 36.9 1.030   15.175 14.889 0.286 1.019   164.89 7.90 156.99 20.874
3 Π Π   619 542 76.9 1.142   14.247 14.263 -0.016 0.999   19.62 4.63 14.99 4.235
4 Π Π   619 542 76.9 1.142   14.247 14.263 -0.016 0.999   19.62 4.63 14.99 4.235
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.