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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

MP2/3-21G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3080 17 A1 3063  
2 A1 3055 12 A1 3043  
3 A1 1498 -74 A1 1572  
4 A1 1362 -52 A1 1414  
5 A1 1169 -114 A1 1283  
6 A1 1066 -94 A1 1160  
7 A1 980 -83 A1 1063  
8 A1 755 -209 A1 964  
9 A1 652 33 A1 619  
10 A2 939 3 A2 936  
11 A2 904 41 A2 863  
12 A2 715 -36 A2 751  
13 A2 347 -74 A2 421  
14 B1 934   B1   760 reassinged to mode 15
15 B1 730 -30 B1 760 696 questionable
16 B1 362 -8 B1 370  
17 B2 3066 -9 B2 3075  
18 B2 3050 7 B2 3043  
19 B2 1463 -102 B2 1565  
20 B2 1377 -67 B2 1444  
21 B2 1230 -9 B2 1239  
22 B2 1039 -13 B2 1052  
23 B2 974 -35 B2 1009  
24 B2 602 -62 B2 664  
The calculated vibrational frequencies were scaled by 0.9513

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.