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Compare vibrational frequencies for two calculations for CH3F+ (methyl fluoride cation)


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)   Raman Activity (Å4/u)
mode number A B   A B diff. ratio   A B diff. ratio   A B diff. ratio   A B diff. ratio
1 A' A'   3080 3114 -34.3 0.989   1.101 1.104 -0.003 0.997   31.68 35.34 -3.66 0.896   38.32 110.87 -72.55 0.346
2 A' A'   2374 2517 -142.4 0.943   1.106 1.061 0.045 1.042   63.04 127.44 -64.40 0.495   97.00 9358.43 -9261.43 0.010
3 A' A'   1447 1412 35.0 1.025   1.848 1.211 0.637 1.526   49.34 15.50 33.84 3.183   8.29 247.97 -239.68 0.033
4 A' A'   1320 1282 38.4 1.030   1.949 1.575 0.374 1.237   112.30 47.34 64.97 2.372   32.73 2968.46 -2935.72 0.011
5 A' A'   1030 1059 -28.3 0.973   1.338 1.306 0.033 1.025   29.00 10.70 18.31 2.711   6.15 214.54 -208.39 0.029
6 A' A'   1002 893 109.6 1.123   1.051 1.947 -0.896 0.540   208.46 126.01 82.45 1.654   54.53 8733.49 -8678.96 0.006
7 A" A"   1837 2244 -407.3 0.818   1.011 1.032 -0.021 0.980   244.10 271.12 -27.02 0.900   63.08 48.56 14.52 1.299
8 A" A"   947 996 -48.5 0.951   1.034 1.021 0.014 1.014   10.06 44.41 -34.35 0.227   13.44 13.31 0.13 1.010
9 A" A"   424 584 -160.2 0.726   1.448 1.419 0.029 1.020   255.92 171.90 84.02 1.489   3.99 0.33 3.66 12.092
scaled by     0.8985 0.943
19 08 20 15 07

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.