return to home page

IV.C.1. (XIII.D.1.)

Compare vibrational frequencies in CCCBDB for C4N2 (2-Butynedinitrile)

BLYP/3-21G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Σg 2285 -5 Σg 2290  
2 Σg 2097 -22 Σg 2119  
3 Σg 606 -86 Σg 692  
4 Σu 2217 -24 Σu 2241  
5 Σu 1167 13 Σu 1154  
6 Πg 936 432 Πg 504  
7 Πg 340 77 Πg 263  
8 Πu 709 237 Πu 472  
9 Πu 118 11 Πu 107  
The calculated vibrational frequencies were scaled by 0.9945

See section XIII.C.3 List or set vibrational scaling factors to change the scale factors used here.
See section III.B.3.c Calculate a vibrational scaling factor for a set of molecules to determine the least squares best scaling factor.
See section III.B.3.b List of vibrational scaling factors and their uncertainties for information on where the above scaling factor is from.