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Compare vibrational frequencies for two calculations for CH2OH (Hydroxymethyl radical)


A = HF/6-31G*
B = MP2/6-31G*

scale factors=0.8985, 0.943 0.264
  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   3705 3582 122.6 1.034   1.067 1.067 0.000 1.000   67.24 51.22 1.313
2 A A   3077 3163 -85.4 0.973   1.119 1.120 -0.002 0.998   37.37 21.19 1.764
3 A A   2954 3017 -63.5 0.979   1.050 1.049 0.001 1.001   37.18 26.37 1.410
4 A A   1462 1459 2.9 1.002   1.160 1.156 0.004 1.004   22.11 11.02 2.006
5 A A   1332 1323 8.8 1.007   1.265 1.271 -0.005 0.996   55.91 33.66 1.661
6 A A   1156 1158 -1.7 0.998   5.443 5.180 1.051   120.64 97.57 1.236
7 A A   1038 1034 4.1 1.004   1.073 1.079 -0.006 0.994   49.31 56.81 0.868
8 A A   769 742 27.4 1.037   1.286 1.280 0.005 1.004   27.42 46.64 0.588
9 A A   370 435 -64.9 0.851   1.077 1.081 -0.004 0.996   141.85 120.64 1.176
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.