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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

PBEPBE/aug-cc-pVDZ

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3117 54 A1 3063  
2 A1 3089 46 A1 3043  
3 A1 1553 -19 A1 1572  
4 A1 1417 3 A1 1414  
5 A1 1180 -103 A1 1283  
6 A1 1117 -43 A1 1160  
7 A1 1057 -6 A1 1063  
8 A1 981 17 A1 964  
9 A1 648 29 A1 619  
10 A2 969 33 A2 936  
11 A2 898 35 A2 863  
12 A2 751 0 A2 751  
13 A2 344 -77 A2 421  
14 B1 933   B1   760 reassinged to mode 15
15 B1 719 -41 B1 760 696 questionable
16 B1 336 -34 B1 370  
17 B2 3104 29 B2 3075  
18 B2 3085 42 B2 3043  
19 B2 1547 -18 B2 1565  
20 B2 1367 -77 B2 1444  
21 B2 1248 9 B2 1239  
22 B2 1043 -9 B2 1052  
23 B2 1013 4 B2 1009  
24 B2 602 -62 B2 664  
The calculated vibrational frequencies were scaled by 0.9939

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.