III.G.7. (XIII.B.3.) (XIII.D.5.) |
Compare vibrational frequencies for two calculations for SiH4+ (Silane 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 | A1 | A1 | 2264 | 2292 | -27.9 | 0.988 | 1.026 | 1.026 | 0.000 | 1.000 | 3.21 | 0.43 | 2.78 | 7.492 | |||
2 | A1 | A1 | 1782 | 1866 | -84.4 | 0.955 | 1.059 | 1.058 | 0.002 | 1.001 | 24.16 | 10.10 | 14.05 | 2.391 | |||
3 | A1 | A1 | 962 | 949 | 13.3 | 1.014 | 1.017 | 1.022 | -0.005 | 0.995 | 34.61 | 39.79 | -5.18 | 0.870 | |||
4 | A1 | A1 | 743 | 641 | 102.4 | 1.160 | 1.056 | 1.053 | 0.004 | 1.004 | 56.89 | 14.90 | 41.99 | 3.818 | |||
5 | A2 | A2 | 649 | 679 | -30.6 | 0.955 | 1.008 | 1.008 | 0.000 | 1.000 | 0.00 | 0.00 | 0.00 | ||||
6 | B1 | B1 | 1239 | 1489 | -250.0 | 0.832 | 1.009 | 1.010 | -0.000 | 1.000 | 434.64 | 211.02 | 223.62 | 2.060 | |||
7 | B1 | B1 | 182i | 483 | -664.9 | -0.376 | 1.135 | 1.133 | 0.002 | 1.002 | 95.33 | 2.50 | 92.83 | 38.166 | |||
8 | B2 | B2 | 2308 | 2345 | -37.5 | 0.984 | 1.062 | 1.063 | -0.001 | 0.999 | 9.02 | 1.13 | 7.89 | 8.011 | |||
9 | B2 | B2 | 770 | 781 | -11.0 | 0.986 | 1.077 | 1.075 | 0.002 | 1.002 | 45.60 | 32.75 | 12.85 | 1.393 | |||
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.