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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

PBEPBE/6-31+G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3108 45 A1 3063  
2 A1 3084 41 A1 3043  
3 A1 1549 -23 A1 1572  
4 A1 1418 4 A1 1414  
5 A1 1177 -106 A1 1283  
6 A1 1122 -38 A1 1160  
7 A1 1054 -9 A1 1063  
8 A1 974 10 A1 964  
9 A1 650 31 A1 619  
10 A2 962 26 A2 936  
11 A2 896 33 A2 863  
12 A2 731 -20 A2 751  
13 A2 340 -81 A2 421  
14 B1 931   B1   760 reassinged to mode 15
15 B1 720 -40 B1 760 696 questionable
16 B1 336 -34 B1 370  
17 B2 3096 21 B2 3075  
18 B2 3079 36 B2 3043  
19 B2 1541 -24 B2 1565  
20 B2 1371 -73 B2 1444  
21 B2 1255 16 B2 1239  
22 B2 1042 -10 B2 1052  
23 B2 1008 -1 B2 1009  
24 B2 602 -62 B2 664  
The calculated vibrational frequencies were scaled by 0.9886

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.