return to home page

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

Compare vibrational frequencies for two calculations for HNO2+ (nitrous acid 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)
mode number A B   A B diff. ratio   A B diff. ratio   A B diff. ratio
1 A' A'   3425 3226 199.2 1.062   1.070 1.085 -0.015 0.986   510.07 185.39 324.68 2.751
2 A' A'   1403 2881 -1478.3 0.487   1.298 11.233 -9.935 0.116   114.83 3048.57 -2933.74 0.038
3 A' A'   1303 1240 62.9 1.051   5.439 1.338 4.102 4.067   102.23 282.82 -180.59 0.361
4 A' A'   1149 1109 40.1 1.036   14.399 6.488 7.911 2.219   203.16 27.29 175.88 7.445
5 A' A'   400 672 -271.9 0.596   8.839 6.204 2.635 1.425   15.99 6.30 9.70 2.540
6 A" A"   689 501 187.6 1.374   1.179 1.268 -0.089 0.930   157.55 159.59 -2.04 0.987
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.