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III.G.7. (XIII.B.3.) (XIII.D.5.)

Compare vibrational frequencies for two calculations for SCN (thiocyanato 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 Σ Σ   1823 2414 -591.2 0.755   12.801 12.868 -0.067 0.995   34.45 1.38 33.07 24.951
2 Σ Σ   679 649 30.4 1.047   17.807 17.680 0.128 1.007   11.82 22.32 -10.51 0.529
3 Π Π   398 415 -17.3 0.958   12.773 12.768 0.005 1.000   5.97 4.54 1.43 1.314
4 Π Π   323 385 -62.2 0.838   12.773 12.768 0.005 1.000   6.79 8.69 -1.91 0.781
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.