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

Compare vibrational frequencies for two calculations for NF3- (Nitrogen trifluoride anion)

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 A1 A1   1112 1002 110.0 1.110   15.483 15.270 0.213 1.014   42.59 38.69 3.90 1.101
2 A1 A1   680 654 25.8 1.039   17.935 16.310 1.625 1.100   7.64 13.71 -6.08 0.557
3 E E   1368 1235 133.3 1.108   15.182 15.183 -0.001 1.000   202.85 272.40 -69.56 0.745
4 E E   522 496 25.7 1.052   18.582 18.497 0.084 1.005   0.41 3.42 -3.02 0.119
5 A E   178 496 -318.5 0.358   18.794 18.497 0.296 1.016   37.74 3.42 34.31 11.024
6 A E   134 496 -362.1 0.270   18.684 18.497 0.187 1.010   3.27 3.42 -0.15 0.955
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.