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

Compare vibrational frequencies for two calculations for H2O2+ (Hydrogen peroxide cation)

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 Ag Ag   3357 3214 143.6 1.045   1.075 1.073 0.002 1.002   0.00 0.00 0.00  
2 Ag Ag   1567 1493 73.5 1.049   1.178 1.155 0.023 1.020   0.00 0.00 0.00  
3 Ag Ag   1404 1009 395.6 1.392   14.398 14.828 -0.430 0.971   0.00 0.00 0.00  
4 Au Au   873 824 49.5 1.060   1.067 1.067 0.000 1.000   388.11 372.17 15.93 1.043
5 Bu Bu   3315 5481 -2166.2 0.605   1.067 1.067 0.000 1.000   1219.06 888014.90 -886795.90 0.001
6 Bu Bu   1290 1268 22.5 1.018   1.067 1.067 0.000 1.000   321.07 578.47 -257.41 0.555
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.