return to home page

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

Compare vibrational frequencies for two calculations for H2CN (H2CN)

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 A1 A1   2908 2921 -13.9 0.995   1.047 1.058 -0.011 0.989   0.22 0.00 0.21 51.381
2 A1 A1   1473 1959 -485.7 0.752   1.770 8.941 -7.170 0.198   12.22 13.23 -1.00 0.924
3 A1 A1   1292 1375 -83.8 0.939   2.099 1.065 1.035 1.972   0.02 17.04 -17.02 0.001
4 B1 B1   928 1106 -177.9 0.839   1.345 1.362 -0.017 0.988   31.84 32.23 -0.39 0.988
5 B2 B2   2983 2986 -2.3 0.999   1.116 1.113 0.003 1.003   16.39 11.25 5.14 1.457
6 B2 B2   964 928 35.3 1.038   1.326 1.353 -0.027 0.980   15.05 7.11 7.95 2.118
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.