III.G.7. (XIII.B.3.) (XIII.D.5.) |
Compare vibrational frequencies for two calculations for HCP+ (Phosphaethyne 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 | Σ | Σ | 3110 | 3141 | -31.0 | 0.990 | 1.102 | 1.113 | -0.011 | 0.990 | 168.64 | 202.13 | -33.49 | 0.834 | |||
2 | Σ | Σ | 963 | 1164 | -201.3 | 0.827 | 7.583 | 7.102 | 0.481 | 1.068 | 0.49 | 4.00 | -3.51 | 0.122 | |||
3 | Π | Π | 533 | 708 | -175.2 | 0.753 | 1.233 | 1.234 | -0.000 | 1.000 | 77.66 | 12.11 | 65.55 | 6.411 | |||
4 | Π | Π | 492 | 565 | -72.8 | 0.871 | 1.233 | 1.234 | -0.000 | 1.000 | 22.88 | 103.55 | -80.68 | 0.221 | |||
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.