return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) 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 NO2 (Nitrogen dioxide)


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 A1 A1   1449 1302 147.2 1.113   15.352 15.293 0.058 1.004   4.19 0.23 3.97 18.625   46.17 3757.60 -3711.43 0.012
2 A1 A1   748 709 38.8 1.055   15.132 15.189 -0.057 0.996   14.75 7.10 7.65 2.078     2094.67    
3 B2 B2   1690 2142 -452.4 0.789   14.617 14.624 -0.007 0.999   757.20 1971.90 -1214.70 0.384   14.70 0.14 14.56 106.974
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.