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
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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 HCONH2CN2H4 (formamide aminomethanimine dimer)

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   3537 3519 18.1 1.005   1.095 1.089 0.005 1.005   107.74 99.13 8.61 1.087
2 A A   3530 3502 27.1 1.008   1.091 1.087 0.004 1.004   106.49 90.92 15.57 1.171
3 A A   3391 3348 42.8 1.013   1.077 1.077 0.000 1.000   2.19 4.62 -2.43 0.474
4 A A   3359 3262 96.8 1.030   1.059 1.064 -0.005 0.995   393.21 627.05 -233.85 0.627
5 A A   3265 3112 152.2 1.049   1.066 1.072 -0.005 0.995   424.33 599.59 -175.26 0.708
6 A A   2945 2955 -10.9 0.996   1.091 1.091 0.001 1.001   78.82 78.91 -0.09 0.999
7 A A   2889 2881 8.3 1.003   1.089 1.088 0.000 1.000   149.62 164.99 -15.37 0.907
8 A A   1766 1723 42.5 1.025   5.067 4.292 0.775 1.181   745.82 490.53 255.29 1.520
9 A A   1706 1684 22.0 1.013   2.357 2.227 0.131 1.059   172.64 94.14 78.50 1.834
10 A A   1647 1608 38.7 1.024   1.359 1.427 -0.068 0.952   24.34 6.54 17.80 3.721
11 A A   1632 1597 34.4 1.022   1.384 1.422 -0.038 0.973   23.94 10.66 13.28 2.246
12 A A   1423 1381 42.0 1.030   1.805 1.970 -0.165 0.916   55.51 30.57 24.94 1.816
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.