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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

MP2/CEP-31G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3113 50 A1 3063  
2 A1 3089 46 A1 3043  
3 A1 1499 -73 A1 1572  
4 A1 1364 -50 A1 1414  
5 A1 1146 -137 A1 1283  
6 A1 1106 -54 A1 1160  
7 A1 991 -72 A1 1063  
8 A1 830 -134 A1 964  
9 A1 625 6 A1 619  
10 A2 876 -60 A2 936  
11 A2 850 -13 A2 863  
12 A2 673 -78 A2 751  
13 A2 346 -75 A2 421  
14 B1 867   B1   760 reassinged to mode 15
15 B1 730 -30 B1 760 696 questionable
16 B1 348 -22 B1 370  
17 B2 3102 27 B2 3075  
18 B2 3066 23 B2 3043  
19 B2 1474 -91 B2 1565  
20 B2 1343 -101 B2 1444  
21 B2 1209 -30 B2 1239  
22 B2 1015 -37 B2 1052  
23 B2 979 -30 B2 1009  
24 B2 582 -82 B2 664  
The calculated vibrational frequencies were scaled by 0.9663

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.