National Institute of Standards and Technology
Computational Chemistry Comparison and Benchmark DataBase
Release 17bSeptember 2015
NIST Standard Reference Database 101
IIntroduction
IIExperimental data
IIICalculated data
IVData comparisons
VCost comparisons
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IXFeedback
XOlder CCCBDB versions
XIIGeometries
XIII Vibrations
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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 HCCO (ketenyl 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 A' A'   3279 3176 103.0 1.032   1.123 1.099 0.023 1.021   106.78 41.80 64.98 2.555
2 A' A'   1880 2328 -448.2 0.807   9.103 11.728 -2.626 0.776   89.18 1048.83 -959.65 0.085
3 A' A'   1255 1235 19.5 1.016   8.097 4.725 3.372 1.714   15.88 27.38 -11.50 0.580
4 A' A'   556 651 -94.4 0.855   4.006 1.295 2.711 3.094   2.10 158.78 -156.68 0.013
5 A' A'   85 583 -497.5 0.146   1.447 9.750 -8.303 0.148   168.96 29.46 139.49 5.734
6 A" A"   481 505 -23.2 0.954   3.649 4.617 -0.968 0.790   9.33 4.88 4.46 1.914
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.