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

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

A = HF/6-31G*

B = MP2FC/6-31G*

  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'   3490 3325 165.2 1.050   1.069 1.070 -0.001 0.999   397.08 345.49 51.59 1.149
2 A' A'   3126 3161 -34.6 0.989   1.134 1.134 0.000 1.000   21.27 19.30 1.97 1.102
3 A' A'   2993 3014 -20.9 0.993   1.059 1.056 0.003 1.003   2.12 6.79 -4.67 0.312
4 A' A'   1642 1604 37.5 1.023   3.459 3.321 0.138 1.042   114.18 31.28 82.90 3.650
5 A' A'   1432 1432 -0.1 1.000   1.276 1.281 -0.005 0.996   83.97 40.82 43.15 2.057
6 A' A'   1338 1322 16.0 1.012   1.385 1.402 -0.017 0.988   125.01 101.19 23.82 1.235
7 A' A'   1071 1068 3.6 1.003   1.055 1.055 0.000 1.000   90.04 88.20 1.85 1.021
8 A" A"   1238 1193 45.1 1.038   1.322 1.308 0.015 1.011   6.25 24.62 -18.37 0.254
9 A" A"   951 1006 -54.8 0.945   1.092 1.096 -0.004 0.997   159.79 132.00 27.79 1.211
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.