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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

BLYP/6-31+G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3111 48 A1 3063  
2 A1 3091 48 A1 3043  
3 A1 1540 -32 A1 1572  
4 A1 1418 4 A1 1414  
5 A1 1150 -133 A1 1283  
6 A1 1124 -36 A1 1160  
7 A1 1042 -21 A1 1063  
8 A1 950 -14 A1 964  
9 A1 655 36 A1 619  
10 A2 971 35 A2 936  
11 A2 904 41 A2 863  
12 A2 730 -21 A2 751  
13 A2 350 -71 A2 421  
14 B1 937   B1   760 reassinged to mode 15
15 B1 729 -31 B1 760 696 questionable
16 B1 346 -24 B1 370  
17 B2 3100 25 B2 3075  
18 B2 3084 41 B2 3043  
19 B2 1530 -35 B2 1565  
20 B2 1381 -63 B2 1444  
21 B2 1258 19 B2 1239  
22 B2 1044 -8 B2 1052  
23 B2 1014 5 B2 1009  
24 B2 609 -55 B2 664  
The calculated vibrational frequencies were scaled by 0.9947

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.