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

Compare vibrational frequencies for two calculations for C4H6OS (2,3-dihydrothiophene-2-ol)

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 A A   3691 3547 143.4 1.040   1.067 1.066 0.001 1.001   69.55 47.27 22.28 1.471
2 A A   3073 3095 -21.5 0.993   1.102 1.101 0.000 1.000   12.59 7.53 5.06 1.671
3 A A   3040 3071 -31.2 0.990   1.089 1.087 0.002 1.002   4.68 0.52 4.16 8.987
4 A A   2931 2983 -52.0 0.983   1.101 1.100 0.001 1.001   54.18 14.67 39.51 3.693
5 A A   2906 2916 -10.6 0.996   1.089 1.080 0.009 1.008   23.32 31.75 -8.43 0.734
6 A A   2887 2910 -22.8 0.992   1.064 1.071 -0.008 0.993   26.90 11.90 15.00 2.260
7 A A   1641 1557 83.3 1.053   6.456 6.233 0.224 1.036   7.80 7.78 0.01 1.002
8 A A   1468 1450 17.3 1.012   1.112 1.107 0.005 1.005   1.71 2.74 -1.03 0.625
9 A A   1415 1380 35.4 1.026   1.430 1.503 -0.074 0.951   6.00 4.57 1.43 1.313
10 A A   1338 1305 32.6 1.025   1.676 1.659 0.017 1.010   13.90 11.24 2.66 1.236
11 A A   1304 1277 27.3 1.021   1.300 1.271 0.028 1.022   21.18 19.71 1.47 1.074
12 A A   1276 1253 23.8 1.019   1.232 1.284 -0.052 0.959   20.92 37.68 -16.76 0.555
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.