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

Compare vibrational frequencies for two calculations for C5H10O (Oxetane, 3,3-dimethyl-)

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'   2936 3009 -73.0 0.976     1.103       97.59 18.86 78.74 5.176
2 A' A'   2934 3004 -69.8 0.977     1.103       76.46 24.34 52.12 3.142
3 A' A'   2925 2967 -42.2 0.986     1.109       31.40 54.97 -23.58 0.571
4 A' A'   2893 2917 -24.2 0.992     1.036       8.33 16.00 -7.67 0.520
5 A' A'   2873 2914 -41.5 0.986     1.035       33.77 19.58 14.18 1.724
6 A' A'   2868 2899 -31.1 0.989     1.061       26.81 31.80 -4.99 0.843
7 A' A'   1524 1502 22.9 1.015     1.117       0.94 1.28 -0.34 0.735
8 A' A'   1481 1476 4.5 1.003     1.062       3.68 4.47 -0.79 0.824
9 A' A'   1468 1463 4.9 1.003     1.054       2.72 3.78 -1.06 0.719
10 A' A'   1415 1389 26.0 1.019     1.244       3.05 3.36 -0.32 0.906
11 A' A'   1401 1373 27.3 1.020     1.354       3.87 10.04 -6.17 0.386
12 A' A'   1386 1336 49.4 1.037     1.821       5.31 0.27 5.04 19.780
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.