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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

MP2/6-31G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3085 22 A1 3063  
2 A1 3063 20 A1 3043  
3 A1 1532 -40 A1 1572  
4 A1 1407 -7 A1 1414  
5 A1 1229 -54 A1 1283  
6 A1 1118 -42 A1 1160  
7 A1 1037 -26 A1 1063  
8 A1 937 -27 A1 964  
9 A1 634 15 A1 619  
10 A2 895 -41 A2 936  
11 A2 878 15 A2 863  
12 A2 647 -104 A2 751  
13 A2 334 -87 A2 421  
14 B1 894   B1   760 reassinged to mode 15
15 B1 715 -45 B1 760 696 questionable
16 B1 344 -26 B1 370  
17 B2 3074 -1 B2 3075  
18 B2 3058 15 B2 3043  
19 B2 1529 -36 B2 1565  
20 B2 1363 -81 B2 1444  
21 B2 1237 -2 B2 1239  
22 B2 1032 -20 B2 1052  
23 B2 999 -10 B2 1009  
24 B2 586 -78 B2 664  
The calculated vibrational frequencies were scaled by 0.9365

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.