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
VIInput and output files
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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 C2H5Br (Ethyl bromide)

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'   2967 3018 -50.8 0.983   1.060 1.099 -0.039 0.965   33.09 13.49 19.61 2.454
2 A' A'   2967 2988 -20.5 0.993   1.060 1.059 0.001 1.001   33.12 8.52 24.60 3.888
3 A' A'   2944 2933 10.7 1.004   1.094 1.038 0.056 1.054   10.55 13.27 -2.72 0.795
4 A' A'   2944 1473 1471.0 1.999   1.094 1.049 0.045 1.043   10.50 2.90 7.60 3.620
5 A' A'   2884 1462 1421.9 1.973   1.041 1.102 -0.061 0.945   28.52 1.24 27.28 23.071
6 A' A'   2884 1387 1496.2 2.079   1.041 1.240 -0.199 0.840   28.56 6.01 22.55 4.754
7 A' A'   1475 1255 220.3 1.175   1.056 1.267 -0.211 0.833   1.40 55.26 -53.85 0.025
8 A' A'   1475 1057 417.9 1.395   1.056 2.187 -1.132 0.483   1.40 0.23 1.17 6.198
9 A' A'   1471 955 516.2 1.541   1.102 1.633 -0.531 0.675   1.33 12.03 -10.70 0.111
10 A' A'   1471 560 911.2 2.627   1.102 4.045 -2.943 0.273   1.33 13.12 -11.78 0.102
11 A' A'   1406 282 1124.1 4.988   1.232 3.200 -1.968 0.385   2.44 1.99 0.45 1.228
12 A' A"   1406 3060 -1653.9 0.459   1.232 1.111 0.121 1.109   2.44 8.73 -6.29 0.279
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.