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Compare vibrational frequencies for two calculations for HOClO (Chlorous acid)


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

scale factors=0.8985, 0.943 7.037 -1.133 1.483 -4.302
  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   3614 3444 169.8 1.049   1.068 1.068 0.000 1.000   133.50 57.51 2.321
2 A A   1264 1135 128.3 1.113   1.097 1.132 -0.035 0.969   63.09 86.75 0.727
3 A A   778 1102 -323.7 0.706   17.881 10.844 1.649   92.19 85.83 1.074
4 A A   747 545 202.3 1.371   15.800 16.933 0.933   35.61 148.61 0.240
5 A A   384 397 -13.6 0.966   2.753 1.270 2.168   132.14 153.01 0.864
6 A A   267 285 -17.8 0.937   1.668 5.970 0.279   62.56 2.12 29.571
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.