return to home page

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

Compare vibrational frequencies for two calculations for C4H6S (Thiophene, 2,3-dihydro-)

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   3073 3098 -24.9 0.992   1.102 1.101 0.001 1.001   12.04 6.44 5.60 1.869
2 A A   3036 3070 -33.1 0.989   1.089 1.088 0.001 1.001   5.56 1.02 4.54 5.451
3 A A   2980 3025 -45.7 0.985   1.107 1.107 0.000 1.000   17.57 7.73 9.84 2.273
4 A A   2930 2975 -45.4 0.985   1.068 1.096 -0.028 0.975   55.67 20.70 34.97 2.690
5 A A   2912 2954 -41.5 0.986   1.091 1.063 0.027 1.026   13.58 13.48 0.10 1.007
6 A A   2870 2903 -33.0 0.989   1.069 1.067 0.002 1.002   46.67 27.80 18.87 1.679
7 A A   1639 1556 82.8 1.053   6.392 6.081 0.311 1.051   7.45 7.54 -0.09 0.988
8 A A   1480 1460 19.2 1.013   1.106 1.105 0.001 1.001   0.94 0.78 0.16 1.199
9 A A   1460 1444 15.8 1.011   1.088 1.093 -0.006 0.995   1.09 2.49 -1.41 0.436
10 A A   1338 1304 33.9 1.026   1.645 1.683 -0.038 0.977   0.23 0.68 -0.45 0.343
11 A A   1314 1293 20.9 1.016   1.330 1.293 0.037 1.028   3.44 3.64 -0.20 0.944
12 A A   1273 1249 23.8 1.019   1.250 1.279 -0.029 0.977   17.54 17.09 0.45 1.027
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.