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
VIInput and output files
VIITutorials and Units
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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 C4H6O (Furan, 2,3-dihydro-)

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   3100 3127 -27.1 0.991   1.109 1.107 0.003 1.002   14.85 5.71 9.13 2.599
2 A A   3074 3103 -28.6 0.991   1.089 1.089 -0.000 1.000   1.69 2.08 -0.39 0.811
3 A A   2965 3019 -54.3 0.982   1.109 1.105 0.004 1.004   60.43 28.02 32.41 2.156
4 A A   2921 2980 -58.7 0.980   1.067 1.100 -0.033 0.970   74.03 19.17 54.86 3.862
5 A A   2905 2931 -26.3 0.991   1.099 1.067 0.032 1.030   19.94 40.94 -21.01 0.487
6 A A   2880 2920 -39.4 0.987   1.063 1.065 -0.002 0.998   55.78 31.01 24.77 1.799
7 A A   1671 1599 72.0 1.045   5.527 5.422 0.105 1.019   76.72 40.63 36.09 1.888
8 A A   1510 1485 24.8 1.017   1.103 1.105 -0.002 0.998   0.43 0.28 0.15 1.563
9 A A   1483 1465 17.4 1.012   1.102 1.102 0.001 1.001   0.19 0.34 -0.15 0.553
10 A A   1402 1358 43.9 1.032   1.530 1.530 -0.001 1.000   6.17 2.42 3.75 2.546
11 A A   1315 1290 25.0 1.019   1.519 1.448 0.072 1.050   5.38 4.48 0.90 1.200
12 A A   1299 1263 35.1 1.028   1.333 1.321 0.013 1.010   7.79 6.20 1.59 1.257
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.