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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

BLYP/6-31G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3104 41 A1 3063  
2 A1 3077 34 A1 3043  
3 A1 1543 -29 A1 1572  
4 A1 1421 7 A1 1414  
5 A1 1150 -133 A1 1283  
6 A1 1123 -37 A1 1160  
7 A1 1043 -20 A1 1063  
8 A1 950 -14 A1 964  
9 A1 655 36 A1 619  
10 A2 971 35 A2 936  
11 A2 905 42 A2 863  
12 A2 734 -17 A2 751  
13 A2 350 -71 A2 421  
14 B1 934   B1   760 reassinged to mode 15
15 B1 731 -29 B1 760 696 questionable
16 B1 345 -25 B1 370  
17 B2 3090 15 B2 3075  
18 B2 3072 29 B2 3043  
19 B2 1534 -31 B2 1565  
20 B2 1384 -60 B2 1444  
21 B2 1258 19 B2 1239  
22 B2 1044 -8 B2 1052  
23 B2 1013 4 B2 1009  
24 B2 608 -56 B2 664  
The calculated vibrational frequencies were scaled by 0.9923

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.