III.G.7. (XIII.B.3.) (XIII.D.5.) |
Compare vibrational frequencies for two calculations for C2H3 (vinyl)
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' | 3081 | 3147 | -65.8 | 0.979 | 1.095 | 1.111 | -0.017 | 0.985 | 3.81 | 1.96 | 1.85 | 1.947 | |||
2 | A' | A' | 3032 | 3086 | -53.9 | 0.983 | 1.110 | 1.108 | 0.001 | 1.001 | 12.02 | 3.95 | 8.08 | 3.047 | |||
3 | A' | A' | 2946 | 2993 | -46.8 | 0.984 | 1.057 | 1.063 | -0.006 | 0.995 | 9.60 | 2.15 | 7.45 | 4.461 | |||
4 | A' | A' | 1468 | 1753 | -284.4 | 0.838 | 1.501 | 5.758 | -4.256 | 0.261 | 1.50 | 2.31 | -0.81 | 0.648 | |||
5 | A' | A' | 1265 | 1382 | -117.2 | 0.915 | 2.441 | 1.083 | 1.357 | 2.253 | 3.39 | 7.83 | -4.44 | 0.433 | |||
6 | A' | A' | 1075 | 1057 | 18.1 | 1.017 | 1.470 | 1.507 | -0.037 | 0.976 | 8.37 | 11.40 | -3.02 | 0.735 | |||
7 | A' | A' | 745 | 726 | 18.4 | 1.025 | 1.053 | 1.054 | -0.001 | 0.999 | 12.52 | 21.12 | -8.60 | 0.593 | |||
8 | A" | A" | 861 | 1004 | -143.1 | 0.857 | 1.190 | 1.212 | -0.022 | 0.982 | 70.31 | 87.56 | -17.25 | 0.803 | |||
9 | A" | A" | 795 | 936 | -141.1 | 0.849 | 1.270 | 1.272 | -0.002 | 0.999 | 2.47 | 10.54 | -8.07 | 0.234 | |||
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.