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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

MP2/6-31+G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3093 30 A1 3063  
2 A1 3075 32 A1 3043  
3 A1 1531 -41 A1 1572  
4 A1 1407 -7 A1 1414  
5 A1 1237 -46 A1 1283  
6 A1 1118 -42 A1 1160  
7 A1 1036 -27 A1 1063  
8 A1 935 -29 A1 964  
9 A1 634 15 A1 619  
10 A2 868 -68 A2 936  
11 A2 860 -3 A2 863  
12 A2 578 -173 A2 751  
13 A2 313 -108 A2 421  
14 B1 877   B1   760 reassinged to mode 15
15 B1 706 -54 B1 760 696 questionable
16 B1 335 -35 B1 370  
17 B2 3083 8 B2 3075  
18 B2 3069 26 B2 3043  
19 B2 1526 -39 B2 1565  
20 B2 1361 -83 B2 1444  
21 B2 1239 0 B2 1239  
22 B2 1032 -20 B2 1052  
23 B2 999 -10 B2 1009  
24 B2 587 -77 B2 664  
The calculated vibrational frequencies were scaled by 0.9406

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.