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

Compare vibrational frequencies for two calculations for C6H10 (Cyclopentene, 4-methyl-)

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   3046 3074 -27.9 0.991   1.105 1.104 0.001 1.001   36.64 24.61 12.03 1.489
2 A A   3021 3051 -30.0 0.990   1.086 1.086 0.001 1.001   13.15 5.46 7.68 2.406
3 A A   2926 3001 -74.9 0.975   1.102 1.103 -0.001 0.999   95.18 21.42 73.76 4.444
4 A A   2924 3001 -77.0 0.974   1.103 1.103 0.000 1.000   45.09 34.55 10.54 1.305
5 A A   2904 2961 -57.1 0.981   1.095 1.098 -0.003 0.997   41.82 31.29 10.53 1.337
6 A A   2898 2958 -60.4 0.980   1.095 1.098 -0.003 0.997   48.79 23.78 25.01 2.052
7 A A   2871 2919 -48.3 0.983   1.082 1.077 0.005 1.005   6.86 22.64 -15.78 0.303
8 A A   2870 2917 -46.5 0.984   1.040 1.042 -0.002 0.998   58.46 17.61 40.85 3.320
9 A A   2854 2894 -39.8 0.986   1.070 1.066 0.004 1.004   37.15 33.40 3.75 1.112
10 A A   2854 2892 -38.7 0.987   1.070 1.068 0.003 1.003   43.31 18.87 24.43 2.295
11 A A   1663 1594 69.3 1.043   6.001 5.701 0.300 1.053   2.42 1.51 0.91 1.604
12 A A   1483 1475 7.5 1.005   1.096 1.055 0.041 1.039   2.66 7.86 -5.20 0.338
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.