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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

PBEPBE/6-31G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3128 65 A1 3063  
2 A1 3108 65 A1 3043  
3 A1 1540 -32 A1 1572  
4 A1 1411 -3 A1 1414  
5 A1 1172 -111 A1 1283  
6 A1 1119 -41 A1 1160  
7 A1 1030 -33 A1 1063  
8 A1 908 -56 A1 964  
9 A1 658 39 A1 619  
10 A2 990 54 A2 936  
11 A2 915 52 A2 863  
12 A2 738 -13 A2 751  
13 A2 348 -73 A2 421  
14 B1 953   B1   760 reassinged to mode 15
15 B1 736 -24 B1 760 696 questionable
16 B1 340 -30 B1 370  
17 B2 3118 43 B2 3075  
18 B2 3097 54 B2 3043  
19 B2 1524 -41 B2 1565  
20 B2 1384 -60 B2 1444  
21 B2 1256 17 B2 1239  
22 B2 1052 0 B2 1052  
23 B2 998 -11 B2 1009  
24 B2 614 -50 B2 664  
The calculated vibrational frequencies were scaled by 0.9862

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.