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Compare vibrational frequencies for two calculations for ClOO (chloroperoxy radical)


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

scale factors=0.8985, 0.943 -2.019 0.439 2.036
  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'   1070 1630 -560.1 0.656   16.075 18.094 0.888   24.23 139.55 0.174
2 A' A'   642 1030 -388.1 0.623   17.468 17.029 1.026   18.33 33.35 0.550
3 A' A'   407 468 -61.3 0.869   20.278 18.242 1.112   1.58 3.07 0.516
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.