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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

MP2/CEP-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3080 17 A1 3063  
2 A1 3059 16 A1 3043  
3 A1 1537 -35 A1 1572  
4 A1 1397 -17 A1 1414  
5 A1 1245 -38 A1 1283  
6 A1 1103 -57 A1 1160  
7 A1 1034 -29 A1 1063  
8 A1 927 -37 A1 964  
9 A1 624 5 A1 619  
10 A2 915 -21 A2 936  
11 A2 877 14 A2 863  
12 A2 704 -47 A2 751  
13 A2 345 -76 A2 421  
14 B1 902   B1   760 reassinged to mode 15
15 B1 740 -20 B1 760 696 questionable
16 B1 353 -17 B1 370  
17 B2 3067 -8 B2 3075  
18 B2 3045 2 B2 3043  
19 B2 1522 -43 B2 1565  
20 B2 1339 -105 B2 1444  
21 B2 1223 -16 B2 1239  
22 B2 1018 -34 B2 1052  
23 B2 995 -14 B2 1009  
24 B2 575 -89 B2 664  
The calculated vibrational frequencies were scaled by 0.9494

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.