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III.G.7. (XIII.B.3.) (XIII.D.5.)

Compare vibrational frequencies for two calculations for C2H3OC2H5 (Ethene, ethoxy-)

A = HF/6-31G*

B = MP2FC/6-31G*

  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   3092 3153 -61.4 0.981   1.119 1.119 -0.000 1.000   14.26 4.64 9.63 3.077
2 A A   3018 3059 -40.6 0.987   1.077 1.064 0.013 1.012   4.44 0.34 4.10 13.127
3 A A   2996 3040 -43.7 0.986   1.078 1.105 -0.027 0.975   22.18 18.04 4.14 1.229
4 A A   2961 3028 -67.8 0.978   1.105 1.103 0.002 1.002   47.95 18.41 29.54 2.604
5 A A   2949 3008 -59.1 0.980   1.102 1.089 0.014 1.013   43.49 20.66 22.83 2.105
6 A A   2898 2945 -46.3 0.984   1.108 1.109 -0.001 0.999   54.37 42.42 11.95 1.282
7 A A   2890 2942 -52.3 0.982   1.038 1.036 0.002 1.002   24.99 11.61 13.38 2.152
8 A A   2866 2895 -28.4 0.990   1.057 1.057 -0.000 1.000   53.30 43.77 9.53 1.218
9 A A   1697 1641 56.5 1.034   4.275 4.348 -0.074 0.983   176.37 111.05 65.32 1.588
10 A A   1510 1498 11.7 1.008   1.097 1.097 0.000 1.000   7.72 6.09 1.64 1.269
11 A A   1478 1475 2.7 1.002   1.058 1.049 0.009 1.008   2.40 3.66 -1.26 0.656
12 A A   1463 1460 3.1 1.002   1.041 1.042 -0.001 0.999   3.27 5.45 -2.19 0.599
13 A A   1434 1403 30.6 1.022   1.318 1.328 -0.010 0.992   19.54 16.85 2.70 1.160
14 A A   1411 1384 26.7 1.019   1.264 1.243 0.021 1.017   57.36 28.14 29.22 2.039
15 A A   1384 1353 31.0 1.023   1.243 1.264 -0.021 0.983   48.94 49.27 -0.33 0.993
16 A A   1320 1294 26.1 1.020   1.188 1.174 0.014 1.012   3.69 3.26 0.43 1.131
17 A A   1284 1259 25.0 1.020   1.097 1.130 -0.033 0.971   1.23 0.22 1.01 5.531
18 A A   1200 1178 21.4 1.018   3.135 2.916 0.220 1.075   233.92 156.62 77.30 1.494
19 A A   1167 1148 18.7 1.016   1.575 1.588 -0.013 0.992   31.87 43.26 -11.39 0.737
20 A A   1147 1115 31.6 1.028   3.312 2.735 0.577 1.211   158.97 99.95 59.02 1.590
21 A A   1068 1061 7.0 1.007   2.108 2.664 -0.556 0.791   14.65 24.88 -10.23 0.589
22 A A   997 955 42.2 1.044   1.157 1.858 -0.701 0.623   14.96 10.78 4.18 1.388
23 A A   958 927 31.1 1.034   2.080 1.095 0.985 1.900   8.15 24.97 -16.83 0.326
24 A A   893 830 62.7 1.075   1.371 1.877 -0.506 0.730   73.96 5.69 68.27 12.995
25 A A   848 799 48.9 1.061   1.818 1.100 0.718 1.653   7.11 0.80 6.31 8.897
26 A A   799 772 26.2 1.034   1.093 1.358 -0.266 0.804   0.22 52.24 -52.03 0.004
27 A A   708 683 25.8 1.038   1.470 1.595 -0.125 0.922   2.04 2.06 -0.02 0.990
28 A A   480 472 7.6 1.016   2.637 2.680 -0.043 0.984   2.67 1.74 0.93 1.532
29 A A   421 420 0.5 1.001   2.946 2.884 0.062 1.021   1.36 1.88 -0.52 0.722
30 A A   246 256 -9.4 0.963   1.127 1.140 -0.013 0.989   0.99 0.79 0.21 1.265
31 A A   207 210 -2.4 0.989   2.561 2.438 0.123 1.051   0.83 0.89 -0.06 0.935
32 A A   86 83 2.7 1.032   3.015 3.028 -0.013 0.996   4.04 3.14 0.89 1.284
33 A A   46 65 -19.1 0.707   2.092 2.125 -0.033 0.984   1.37 1.54 -0.17 0.892
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.