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

Compare vibrational frequencies for two calculations for C4H6O (Furan, 2,3-dihydro-)

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   3100 3127 -27.1 0.991   1.109 1.107 0.003 1.002   14.85 5.70 9.14 2.604
2 ?a ?a   3074 3103 -28.5 0.991   1.089 1.089 -0.000 1.000   1.69 2.10 -0.41 0.803
3 ?a ?a   2965 3019 -54.3 0.982   1.109 1.105 0.004 1.004   60.43 28.04 32.39 2.155
4 ?a ?a   2921 2980 -58.8 0.980   1.067 1.100 -0.033 0.970   74.03 19.15 54.88 3.866
5 ?a ?a   2905 2931 -26.2 0.991   1.099 1.067 0.032 1.030   19.94 40.97 -21.03 0.487
6 ?a ?a   2880 2920 -39.6 0.986   1.063 1.065 -0.002 0.998   55.78 31.01 24.77 1.799
7 ?a ?a   1671 1599 72.3 1.045   5.527 5.419 0.108 1.020   76.72 40.65 36.07 1.887
8 ?a ?a   1510 1485 24.9 1.017   1.103 1.105 -0.002 0.998   0.43 0.28 0.15 1.553
9 ?a ?a   1483 1465 17.5 1.012   1.102 1.102 0.001 1.000   0.19 0.34 -0.15 0.551
10 ?a ?a   1402 1358 43.9 1.032   1.530 1.531 -0.001 0.999   6.17 2.43 3.74 2.541
11 ?a ?a   1315 1290 24.9 1.019   1.519 1.447 0.072 1.050   5.38 4.46 0.92 1.205
12 ?a ?a   1299 1263 35.1 1.028   1.333 1.321 0.012 1.009   7.79 6.22 1.57 1.253
13 ?a ?a   1236 1201 35.3 1.029   1.092 1.235 -0.143 0.884   2.30 14.38 -12.08 0.160
14 ?a ?a   1197 1172 25.1 1.021   1.232 1.269 -0.036 0.972   9.48 12.62 -3.14 0.751
15 ?a ?a   1157 1123 34.2 1.030   1.831 1.434 0.397 1.277   100.52 47.96 52.57 2.096
16 ?a ?a   1083 1058 24.8 1.023   2.127 2.178 -0.051 0.976   64.55 27.49 37.06 2.348
17 ?a ?a   1066 1041 25.0 1.024   1.562 1.831 -0.269 0.853   3.91 28.40 -24.49 0.138
18 ?a ?a   988 981 7.0 1.007   2.977 2.373 0.603 1.254   23.58 4.63 18.95 5.093
19 ?a ?a   954 917 36.7 1.040   1.348 2.786 -1.438 0.484   0.75 11.62 -10.87 0.064
20 ?a ?a   924 913 11.2 1.012   2.573 2.309 0.264 1.114   40.20 33.64 6.56 1.195
21 ?a ?a   897 841 55.9 1.066   2.753 1.331 1.422 2.068   19.30 5.35 13.95 3.607
22 ?a ?a   823 825 -2.5 0.997   1.583 1.733 -0.150 0.914   3.48 7.41 -3.93 0.469
23 ?a ?a   813 794 18.4 1.023   3.200 5.095 -1.895 0.628   6.30 6.71 -0.41 0.939
24 ?a ?a   738 684 54.3 1.079   1.195 1.212 -0.017 0.986   36.45 34.15 2.30 1.067
25 ?a ?a   685 632 53.3 1.084   4.468 2.947 1.521 1.516   2.61 1.57 1.04 1.661
26 ?a ?a   441 426 15.6 1.037   2.418 2.610 -0.192 0.926   25.50 24.03 1.47 1.061
27 ?a ?a   59 155 -95.3 0.384   1.994 1.980 0.014 1.007   2.74 2.10 0.64 1.307
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.