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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

PBEPBE/6-311+G(3df,2p)

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3094 31 A1 3063  
2 A1 3066 23 A1 3043  
3 A1 1548 -24 A1 1572  
4 A1 1419 5 A1 1414  
5 A1 1168 -115 A1 1283  
6 A1 1124 -36 A1 1160  
7 A1 1055 -8 A1 1063  
8 A1 979 15 A1 964  
9 A1 652 33 A1 619  
10 A2 980 44 A2 936  
11 A2 905 42 A2 863  
12 A2 748 -3 A2 751  
13 A2 342 -79 A2 421  
14 B1 943   B1   760 reassinged to mode 15
15 B1 726 -34 B1 760 696 questionable
16 B1 337 -33 B1 370  
17 B2 3080 5 B2 3075  
18 B2 3061 18 B2 3043  
19 B2 1538 -27 B2 1565  
20 B2 1376 -68 B2 1444  
21 B2 1258 19 B2 1239  
22 B2 1045 -7 B2 1052  
23 B2 1014 5 B2 1009  
24 B2 604 -60 B2 664  
The calculated vibrational frequencies were scaled by 0.9918

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.