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
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 C4H4N (pyrrolide 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   3096 3126 -29.8 0.990   1.108 1.107 0.001 1.001   3.08 0.46 2.62 6.723
2 A1 A1   3065 3092 -26.7 0.991   1.095 1.097 -0.002 0.998   6.77 1.01 5.76 6.717
3 A1 A1   1548 1523 24.9 1.016   4.253 3.565 0.689 1.193   0.22 11.42 -11.19 0.019
4 A1 A1   1426 1394 32.0 1.023   3.013 4.843 -1.829 0.622   22.98 28.80 -5.82 0.798
5 A1 A1   1145 1204 -58.2 0.952   1.916 2.415 -0.499 0.793   0.29 12.40 -12.10 0.024
6 A1 A1   1067 1067 -0.8 0.999   1.380 1.759 -0.379 0.785   28.78 40.46 -11.68 0.711
7 A1 A1   985 1039 -53.8 0.948   2.331 1.354 0.977 1.722   1.40 3.41 -2.01 0.410
8 A1 A1   848 848 -0.3 1.000   5.587 4.671 0.916 1.196   13.15 12.72 0.42 1.033
9 A2 A2   940 836 103.7 1.124   1.331 1.522 -0.191 0.874   0.00 0.00 0.00  
10 A2 A2   783 778 4.6 1.006   1.540 1.182 0.358 1.303   0.00 0.00 0.00  
11 A2 A2   502 470 31.6 1.067   2.245 2.923 -0.678 0.768   0.00 0.00 0.00  
12 B1 B1   794 833 -38.3 0.954   1.589 1.770 -0.181 0.898   12.78 0.09 12.69 141.669
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.