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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 3102 39 A1 3063  
2 A1 3077 34 A1 3043  
3 A1 1546 -26 A1 1572  
4 A1 1425 11 A1 1414  
5 A1 1154 -129 A1 1283  
6 A1 1126 -34 A1 1160  
7 A1 1044 -19 A1 1063  
8 A1 949 -15 A1 964  
9 A1 655 36 A1 619  
10 A2 968 32 A2 936  
11 A2 905 42 A2 863  
12 A2 733 -18 A2 751  
13 A2 351 -70 A2 421  
14 B1 931   B1   760 reassinged to mode 15
15 B1 730 -30 B1 760 696 questionable
16 B1 346 -24 B1 370  
17 B2 3089 14 B2 3075  
18 B2 3072 29 B2 3043  
19 B2 1536 -29 B2 1565  
20 B2 1390 -54 B2 1444  
21 B2 1264 25 B2 1239  
22 B2 1046 -6 B2 1052  
23 B2 1013 4 B2 1009  
24 B2 608 -56 B2 664  
The calculated vibrational frequencies were scaled by 0.9919

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.