III.G.7. (XIII.B.3.) (XIII.D.5.) |
Compare vibrational frequencies for two calculations for HCOOHH2O (Formic acid water 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 | A | A | 3735 | 3634 | 101.2 | 1.028 | 1.080 | 1.075 | 0.005 | 1.004 | 128.30 | 99.10 | 29.20 | 1.295 | |||
2 | A | A | 3616 | 3457 | 158.7 | 1.046 | 1.049 | 1.052 | -0.003 | 0.997 | 104.51 | 158.16 | -53.65 | 0.661 | |||
3 | A | A | 3436 | 3130 | 305.9 | 1.098 | 1.066 | 1.066 | -0.000 | 1.000 | 487.21 | 564.51 | -77.30 | 0.863 | |||
4 | A | A | 2978 | 2982 | -3.2 | 0.999 | 1.094 | 1.092 | 0.002 | 1.002 | 76.45 | 96.65 | -20.20 | 0.791 | |||
5 | A | A | 1794 | 1705 | 89.3 | 1.052 | 6.895 | 5.144 | 1.751 | 1.340 | 465.42 | 260.71 | 204.71 | 1.785 | |||
6 | A | A | 1645 | 1644 | 0.6 | 1.000 | 1.084 | 1.112 | -0.028 | 0.975 | 143.35 | 141.06 | 2.29 | 1.016 | |||
7 | A | A | 1414 | 1418 | -4.0 | 0.997 | 1.187 | 1.259 | -0.073 | 0.942 | 5.03 | 1.41 | 3.62 | 3.572 | |||
8 | A | A | 1371 | 1348 | 22.7 | 1.017 | 1.465 | 1.263 | 0.202 | 1.160 | 28.80 | 12.31 | 16.49 | 2.339 | |||
9 | A | A | 1206 | 1181 | 25.2 | 1.021 | 3.498 | 4.194 | -0.696 | 0.834 | 281.24 | 218.42 | 62.82 | 1.288 | |||
10 | A | A | 1082 | 1031 | 51.0 | 1.049 | 1.592 | 1.358 | 0.234 | 1.172 | 0.73 | 26.90 | -26.18 | 0.027 | |||
11 | A | A | 842 | 925 | -82.9 | 0.910 | 1.143 | 1.270 | -0.127 | 0.900 | 239.51 | 152.03 | 87.48 | 1.575 | |||
12 | A | A | 672 | 682 | -9.5 | 0.986 | 4.159 | 2.340 | 1.819 | 1.777 | 66.83 | 162.39 | -95.56 | 0.412 | |||
13 | A | A | 520 | 617 | -97.2 | 0.842 | 1.124 | 1.460 | -0.336 | 0.770 | 244.33 | 173.89 | 70.44 | 1.405 | |||
14 | A | A | 316 | 360 | -44.3 | 0.877 | 1.223 | 1.236 | -0.013 | 0.989 | 115.18 | 101.10 | 14.08 | 1.139 | |||
15 | A | A | 222 | 286 | -64.1 | 0.776 | 1.202 | 1.136 | 0.067 | 1.059 | 77.83 | 80.76 | -2.93 | 0.964 | |||
16 | A | A | 196 | 236 | -40.1 | 0.830 | 6.550 | 6.411 | 0.139 | 1.022 | 29.89 | 41.29 | -11.40 | 0.724 | |||
17 | A | A | 161 | 190 | -29.9 | 0.843 | 1.675 | 3.289 | -1.614 | 0.509 | 52.74 | 26.46 | 26.28 | 1.993 | |||
18 | A | A | 149 | 185 | -36.5 | 0.803 | 4.265 | 2.242 | 2.023 | 1.902 | 7.98 | 7.88 | 0.10 | 1.013 | |||
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.