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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

BLYP/6-311G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3100 37 A1 3063  
2 A1 3073 30 A1 3043  
3 A1 1536 -36 A1 1572  
4 A1 1413 -1 A1 1414  
5 A1 1143 -140 A1 1283  
6 A1 1116 -44 A1 1160  
7 A1 1037 -26 A1 1063  
8 A1 946 -18 A1 964  
9 A1 658 39 A1 619  
10 A2 975 39 A2 936  
11 A2 906 43 A2 863  
12 A2 739 -12 A2 751  
13 A2 350 -71 A2 421  
14 B1 940   B1   760 reassinged to mode 15
15 B1 731 -29 B1 760 696 questionable
16 B1 345 -25 B1 370  
17 B2 3086 11 B2 3075  
18 B2 3068 25 B2 3043  
19 B2 1525 -40 B2 1565  
20 B2 1383 -61 B2 1444  
21 B2 1258 19 B2 1239  
22 B2 1044 -8 B2 1052  
23 B2 1019 10 B2 1009  
24 B2 614 -50 B2 664  
The calculated vibrational frequencies were scaled by 0.9961

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.