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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

QCISD/6-31G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3091 28 A1 3063  
2 A1 3068 25 A1 3043  
3 A1 1568 -4 A1 1572  
4 A1 1425 11 A1 1414  
5 A1 1131 -152 A1 1283  
6 A1 1103 -57 A1 1160  
7 A1 1044 -19 A1 1063  
8 A1 938 -26 A1 964  
9 A1 644 25 A1 619  
10 A2 918 -18 A2 936  
11 A2 896 33 A2 863  
12 A2 671 -80 A2 751  
13 A2 341 -80 A2 421  
14 B1 913   B1   760 reassinged to mode 15
15 B1 727 -33 B1 760 696 questionable
16 B1 355 -15 B1 370  
17 B2 3079 4 B2 3075  
18 B2 3063 20 B2 3043  
19 B2 1563 -2 B2 1565  
20 B2 1391 -53 B2 1444  
21 B2 1264 25 B2 1239  
22 B2 1041 -11 B2 1052  
23 B2 1003 -6 B2 1009  
24 B2 596 -68 B2 664  
The calculated vibrational frequencies were scaled by 0.9414

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.