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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

MP2/CEP-121G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3102 39 A1 3063  
2 A1 3082 39 A1 3043  
3 A1 1504 -68 A1 1572  
4 A1 1378 -36 A1 1414  
5 A1 1153 -130 A1 1283  
6 A1 1109 -51 A1 1160  
7 A1 990 -73 A1 1063  
8 A1 826 -138 A1 964  
9 A1 634 15 A1 619  
10 A2 817 -119 A2 936  
11 A2 769 -94 A2 863  
12 A2 374 -377 A2 751  
13 B1 783 362 A2 421  
14 B1 709   B1   760 reassinged to mode 15
15 B1 337 -423 B1 760 696 questionable
16 B2 3093 2723 B1 370  
17 B2 3069 -6 B2 3075  
18 B2 1483 -1560 B2 3043  
19 B2 1359 -206 B2 1565  
20 B2 1224 -220 B2 1444  
21 B2 1029 -210 B2 1239  
22 B2 983 -69 B2 1052  
23 B2 593 -416 B2 1009  
24   -664 B2 664  
The calculated vibrational frequencies were scaled by 0.976

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.