III.G.7. (XIII.B.3.) (XIII.D.5.) |
Compare vibrational frequencies for two calculations for C4+ (Carbon tetramer cation)
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 | Σg | Σg | 2136 | 1973 | 162.7 | 1.082 | 12.000 | 12.000 | 0.000 | 1.000 | 0.00 | 0.00 | 0.00 | ||||
2 | Σg | Σg | 853 | 873 | -20.3 | 0.977 | 12.000 | 12.000 | 0.000 | 1.000 | 0.00 | 0.00 | 0.00 | ||||
3 | Σu | Σu | 1202 | 1423 | -221.8 | 0.844 | 12.000 | 12.000 | 0.000 | 1.000 | 114.49 | 2262.61 | -2148.12 | 0.051 | |||
4 | Πg | Πg | 327 | 265 | 62.4 | 1.236 | 12.000 | 12.000 | 0.000 | 1.000 | 0.00 | 0.00 | 0.00 | ||||
5 | Πg | Πg | 244 | 207 | 37.1 | 1.179 | 12.000 | 12.000 | 0.000 | 1.000 | 0.00 | 0.00 | 0.00 | ||||
6 | Πu | Πu | 170 | 134 | 36.5 | 1.273 | 12.000 | 12.000 | 0.000 | 1.000 | 7.70 | 1.57 | 6.13 | 4.909 | |||
7 | Πu | Πu | 146 | 129 | 17.0 | 1.132 | 12.000 | 12.000 | 0.000 | 1.000 | 6.33 | 7.38 | -1.05 | 0.858 | |||
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.