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Compare vibrational frequencies for two calculations for Be(OH)2 (Beryllium hydroxide)


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)   Raman Activity (Å4/u)
mode number A B   A B diff. ratio   A B diff. ratio   A B diff. ratio   A B diff. ratio
1 A A1   3786 3712 73.8 1.020   1.068 1.068 0.000 1.000   39.39 57.36 -17.98 0.687          
2 A A1   689 698 -9.8 0.986   6.557 5.049 1.508 1.299   4.04 10.49 -6.45 0.385          
3 A A1   512 550 -38.6 0.930   1.574 1.902 -0.328 0.827   131.94 185.03 -53.09 0.713          
4 A A1   288 262 25.7 1.098   2.984 2.250 0.734 1.326   76.21 4.77 71.45 15.982          
5 A A2   184 230i 414.5 -0.800   1.079 1.128 -0.049 0.957   155.46 0.00 155.46            
6 B B1   3784 320 3463.2 11.806   1.068 7.963 -6.895 0.134   193.07 69.55 123.52 2.776          
7 B B2   1430 3710 -2279.5 0.386   8.179 1.068 7.110 7.655   438.23 164.78 273.45 2.660          
8 B B2   512 1456 -944.4 0.351   1.577 7.961 -6.383 0.198   455.98 340.32 115.67 1.340          
9 B B2   273 416 -143.3 0.656   2.676 1.157 1.519 2.313   125.99 357.10 -231.10 0.353          
scaled by     0.8985 0.943
19 08 20 15 07

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.