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 C2H5 (Ethyl 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'   2978 3060 -81.6 0.973   1.051 1.051 0.000 1.000   19.08 12.83 6.25 1.487
2 A' A'   2901 2973 -71.2 0.976   1.080 1.086 -0.006 0.995   41.85 21.83 20.02 1.917
3 A' A'   2840 2892 -52.1 0.982   1.053 1.048 0.005 1.005   40.16 20.65 19.51 1.945
4 A' A'   1465 1463 1.2 1.001   1.067 1.104 -0.037 0.966   3.46 3.68 -0.22 0.940
5 A' A'   1445 1450 -4.5 0.997   1.171 1.126 0.045 1.040   1.82 2.59 -0.78 0.700
6 A' A'   1395 1385 9.5 1.007   1.188 1.207 -0.019 0.985   0.00 1.39 -1.39 0.001
7 A' A'   1000 1044 -43.7 0.958   2.776 3.160 -0.384 0.878   0.45 0.06 0.40 7.937
8 A' A'   973 971 2.3 1.002   1.416 1.324 0.092 1.070   0.04 0.38 -0.33 0.117
9 A' A'   413 438 -24.6 0.944   1.220 1.217 0.003 1.002   45.34 54.36 -9.02 0.834
10 A" A"   3066 3162 -95.6 0.970   1.119 1.119 -0.000 1.000   28.95 13.96 14.99 2.073
11 A" A"   2932 3015 -82.4 0.973   1.104 1.103 0.000 1.000   36.26 18.26 18.00 1.985
12 A" A"   1469 1469 0.2 1.000   1.039 1.038 0.001 1.001   2.91 4.61 -1.71 0.630
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.