return to home page

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

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

MP2=FULL/6-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Σg 2138 -152 Σg 2290  
2 Σg 1937 -182 Σg 2119  
3 Σg 573 -119 Σg 692  
4 Σu 2053 -188 Σu 2241  
5 Σu 1104 -50 Σu 1154  
6 Πg 563 59 Πg 504  
7 Πg 268 5 Πg 263  
8 Πu 498 26 Πu 472  
9 Πu 111 4 Πu 107  
The calculated vibrational frequencies were scaled by 0.9422

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.