III.G.7. (XIII.B.3.) (XIII.D.5.) |
Compare vibrational frequencies for two calculations for H2Ar (H2 Ar dimer)
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 | Σ | Σ | 4175 | 4275 | -100.4 | 0.977 | 1.008 | 1.008 | 0.000 | 1.000 | 0.01 | 0.03 | -0.02 | 0.174 | |||
2 | Σ | Σ | 27 | 48 | -21.2 | 0.557 | 1.057 | 1.057 | 0.000 | 1.000 | 0.00 | 0.02 | -0.02 | 0.202 | |||
3 | Π | Π | 32 | 78 | -45.2 | 0.418 | 1.008 | 1.008 | -0.000 | 1.000 | 0.00 | 0.00 | -0.00 | 0.636 | |||
4 | Π | Π | 32 | 78 | -45.2 | 0.418 | 1.008 | 1.008 | -0.000 | 1.000 | 0.00 | 0.00 | -0.00 | 0.636 | |||
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.