return to home page

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

Compare vibrational frequencies for two calculations for C4H8O2 (1,3-Dioxolane, 2-methyl-)

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   2974 3047 -72.9 0.976   1.099 1.105 -0.006 0.995   55.05 12.32 42.73 4.469
2 A A   2968 3037 -68.6 0.977   1.105 1.104 0.001 1.001   35.41 10.21 25.20 3.469
3 A A   2959 3020 -61.0 0.980   1.104 1.101 0.003 1.003   28.58 23.83 4.75 1.199
4 A A   2945 2989 -44.0 0.985   1.106 1.108 -0.002 0.998   58.97 33.01 25.96 1.786
5 A A   2905 2945 -40.2 0.986   1.061 1.035 0.027 1.026   57.01 5.87 51.14 9.714
6 A A   2896 2930 -33.9 0.988   1.037 1.060 -0.023 0.978   19.46 47.77 -28.32 0.407
7 A A   2878 2905 -27.0 0.991   1.073 1.069 0.003 1.003   76.62 44.04 32.58 1.740
8 A A   2855 2855 -0.6 1.000   1.084 1.086 -0.002 0.999   86.73 83.21 3.51 1.042
9 A A   1519 1498 21.2 1.014   1.118 1.106 0.012 1.011   0.39 0.31 0.08 1.256
10 A A   1502 1479 23.3 1.016   1.107 1.105 0.002 1.002   1.52 2.82 -1.30 0.539
11 A A   1467 1461 6.1 1.004   1.087 1.051 0.036 1.035   11.17 4.21 6.96 2.652
12 A A   1466 1458 7.6 1.005   1.066 1.051 0.015 1.014   4.87 2.04 2.83 2.389
13 A A   1441 1406 35.1 1.025   1.488 1.597 -0.109 0.932   86.48 74.42 12.06 1.162
14 A A   1394 1363 30.4 1.022   1.364 1.240 0.124 1.100   23.01 2.72 20.29 8.465
15 A A   1389 1346 42.4 1.032   1.241 1.321 -0.080 0.940   5.10 9.89 -4.80 0.515
16 A A   1379 1338 41.3 1.031   1.372 1.322 0.050 1.038   11.22 8.14 3.08 1.378
17 A A   1332 1289 43.4 1.034   1.173 1.183 -0.009 0.992   1.41 1.54 -0.13 0.917
18 A A   1241 1210 30.7 1.025   1.241 1.264 -0.023 0.981   30.38 18.66 11.73 1.629
19 A A   1216 1184 32.0 1.027   1.161 1.217 -0.056 0.954   3.82 3.11 0.71 1.227
20 A A   1178 1149 29.5 1.026   3.052 2.273 0.779 1.343   235.30 65.40 169.90 3.598
21 A A   1155 1122 32.6 1.029   2.083 2.157 -0.074 0.966   45.27 56.90 -11.62 0.796
22 A A   1128 1105 23.0 1.021   2.407 2.145 0.263 1.123   55.99 55.52 0.47 1.009
23 A A   1114 1083 30.5 1.028   1.895 1.880 0.015 1.008   31.35 49.80 -18.45 0.629
24 A A   1076 1031 44.7 1.043   2.891 3.638 -0.747 0.795   6.87 19.81 -12.94 0.347
25 A A   1041 1009 31.8 1.032   3.414 3.391 0.024 1.007   40.10 40.58 -0.48 0.988
26 A A   929 930 -1.5 0.998   2.403 2.331 0.072 1.031   14.55 15.25 -0.70 0.954
27 A A   896 876 19.6 1.022   2.017 1.766 0.251 1.142   49.77 2.03 47.74 24.505
28 A A   875 858 17.0 1.020   1.642 2.187 -0.545 0.751   8.82 47.39 -38.58 0.186
29 A A   833 813 20.1 1.025   2.773 2.763 0.010 1.004   5.52 10.85 -5.33 0.509
30 A A   693 668 25.1 1.038   4.881 5.592 -0.712 0.873   2.87 1.68 1.19 1.711
31 A A   660 625 35.7 1.057   2.450 2.386 0.065 1.027   5.02 3.54 1.49 1.420
32 A A   482 482 0.6 1.001   2.810 2.789 0.021 1.008   7.50 6.73 0.77 1.114
33 A A   324 323 0.9 1.003   2.793 2.776 0.017 1.006   5.44 5.79 -0.36 0.938
34 A A   229 245 -15.3 0.938   1.115 1.424 -0.309 0.783   0.16 0.91 -0.75 0.178
35 A A   193 226 -33.2 0.853   1.954 1.387 0.567 1.409   3.77 2.17 1.60 1.740
36 A A   57 53 4.2 1.079   2.796 2.937 -0.141 0.952   6.98 6.65 0.33 1.050
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.