III.G.7. (XIII.B.3.) (XIII.D.5.) |
Compare vibrational frequencies for two calculations for CCl2- (dichloromethylene anion)
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 | A1 | A1 | 491 | 549 | -58.6 | 0.893 | 13.536 | 13.700 | -0.164 | 0.988 | 74.28 | 39.49 | 34.79 | 1.881 | |||
2 | A1 | A1 | 209 | 234 | -25.2 | 0.892 | 33.296 | 32.342 | 0.954 | 1.029 | 8.03 | 4.31 | 3.72 | 1.862 | |||
3 | B2 | B2 | 298 | 450 | -152.3 | 0.662 | 13.992 | 13.984 | 0.009 | 1.001 | 451.65 | 270.31 | 181.34 | 1.671 | |||
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.