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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

MP2/cc-pVDZ

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3100 37 A1 3063  
2 A1 3076 33 A1 3043  
3 A1 1536 -36 A1 1572  
4 A1 1409 -5 A1 1414  
5 A1 1248 -35 A1 1283  
6 A1 1104 -56 A1 1160  
7 A1 1042 -21 A1 1063  
8 A1 950 -14 A1 964  
9 A1 635 16 A1 619  
10 A2 942 6 A2 936  
11 A2 894 31 A2 863  
12 A2 702 -49 A2 751  
13 A2 347 -74 A2 421  
14 B1 923   B1   760 reassinged to mode 15
15 B1 725 -35 B1 760 696 questionable
16 B1 353 -17 B1 370  
17 B2 3088 13 B2 3075  
18 B2 3071 28 B2 3043  
19 B2 1537 -28 B2 1565  
20 B2 1354 -90 B2 1444  
21 B2 1234 -5 B2 1239  
22 B2 1029 -23 B2 1052  
23 B2 1008 -1 B2 1009  
24 B2 587 -77 B2 664  
The calculated vibrational frequencies were scaled by 0.9525

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.