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Compare vibrational frequencies for two calculations for CH2D2 (methane-d2)


A = HF/6-31G*
B = MP2/6-31G*

scale factors=0.8985, 0.943 1.130 1.096 0.202 1.273 0.601
  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 A1 A1   2924 3062 -138.5 0.955   1.063 1.103 -0.039 0.964   22.02 19.69 1.118
2 A1 A1   2111 2933 -821.9 0.720   2.137 1.008 2.121   7.11 0.00  
3 A1 A1   1442 1532 -90.7 0.941   1.069 1.008 0.061 1.061   4.09 0.00  
4 A1 A1   1040 1333 -293.4 0.780   2.274 1.178 1.930   4.47 15.99 0.280
5 A2 A2   1325 1532 -207.2 0.865   1.209 1.008 1.200   0.00 0.00  
6 B1 B1   2198 3062 -864.4 0.718   2.375 1.103 2.154   18.77 19.70 0.953
7 B1 B1   1257 1333 -76.4 0.943   1.267 1.178 0.089 1.075   10.09 15.99 0.631
8 B2 B2   2966 3063 -96.4 0.969   1.103 1.103 0.001 1.001   39.39 19.69 2.001
9 B2 B2   1109 1333 -224.1 0.832   1.779 1.178 1.510   7.13 15.99 0.446
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.