return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Comparisons > Vibrations > Vibrations > 2 calculations

Compare vibrational frequencies for two calculations for ClCO (carbonyl monochloride)


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

scale factors=0.8985, 0.943 -0.151
  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'   1947 1883 64.7 1.034   13.559 13.493 0.066 1.005   524.49 526.94 0.995
2 A' A'   518 609 -91.3 0.850   13.254 13.246 0.008 1.001   66.73 148.31 0.450
3 A' A'   174 359 -184.7 0.485   18.712 18.863 0.992   83.93 32.77 2.561
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.