return to home page

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

Compare vibrational frequencies for two calculations for C3H6S (Thietane)

A = HF/6-31G*

B = MP2FC/6-31G*

  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'   2986 3030 -44.1 0.985   1.111 1.110 0.001 1.001   45.52 24.64 20.88 1.848
2 A' A'   2948 3005 -56.1 0.981   1.106 1.108 -0.002 0.998   17.11 7.09 10.02 2.414
3 A' A'   2934 2961 -26.8 0.991   1.065 1.061 0.004 1.004   16.50 13.76 2.74 1.199
4 A' A'   2908 2946 -38.0 0.987   1.060 1.060 0.000 1.000   39.04 30.05 8.99 1.299
5 A' A'   1496 1484 12.6 1.009   1.126 1.121 0.006 1.005   1.84 1.64 0.20 1.122
6 A' A'   1463 1456 6.3 1.004   1.082 1.083 -0.001 0.999   1.77 3.70 -1.93 0.479
7 A' A'   1262 1241 21.1 1.017   1.364 1.377 -0.013 0.990   4.64 2.69 1.95 1.726
8 A' A'   1189 1175 13.5 1.012   1.382 1.448 -0.066 0.955   0.67 1.50 -0.84 0.444
9 A' A'   978 981 -2.9 0.997   1.325 1.360 -0.035 0.974   2.17 3.72 -1.54 0.585
10 A' A'   907 931 -23.8 0.974   2.798 2.500 0.298 1.119   0.03 0.11 -0.08 0.269
11 A' A'   826 853 -26.7 0.969   2.185 1.817 0.369 1.203   5.65 2.85 2.79 1.979
12 A' A'   700 692 7.7 1.011   1.626 2.057 -0.431 0.790   4.41 2.52 1.89 1.748
13 A' A'   534 517 17.2 1.033   5.093 4.115 0.978 1.238   3.36 2.35 1.01 1.429
14 A' A'   116 181 -65.1 0.640   1.767 1.774 -0.007 0.996   1.90 1.74 0.16 1.093
15 A" A"   2982 3027 -45.3 0.985   1.111 1.110 0.001 1.001   6.16 6.17 -0.01 0.999
16 A" A"   2932 2961 -29.2 0.990   1.058 1.058 0.000 1.000   86.22 45.65 40.57 1.889
17 A" A"   1472 1459 13.1 1.009   1.098 1.092 0.006 1.006   0.62 0.12 0.51 5.363
18 A" A"   1299 1278 20.8 1.016   1.407 1.387 0.019 1.014   2.33 2.09 0.24 1.115
19 A" A"   1241 1224 16.7 1.014   1.187 1.223 -0.036 0.970   14.07 15.37 -1.31 0.915
20 A" A"   1197 1167 30.0 1.026   1.264 1.340 -0.076 0.943   6.70 4.53 2.17 1.480
21 A" A"   1026 1014 12.2 1.012   1.027 1.028 -0.001 0.999   0.04 0.19 -0.15 0.193
22 A" A"   948 966 -18.4 0.981   2.244 1.997 0.247 1.124   0.51 0.28 0.23 1.842
23 A" A"   808 816 -7.9 0.990   1.209 1.227 -0.018 0.985   0.01 0.17 -0.16 0.052
24 A" A"   683 677 5.8 1.009   5.677 5.343 0.334 1.063   4.38 1.52 2.86 2.884
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.