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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

PBEPBE/6-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3101 38 A1 3063  
2 A1 3074 31 A1 3043  
3 A1 1553 -19 A1 1572  
4 A1 1425 11 A1 1414  
5 A1 1177 -106 A1 1283  
6 A1 1126 -34 A1 1160  
7 A1 1056 -7 A1 1063  
8 A1 973 9 A1 964  
9 A1 650 31 A1 619  
10 A2 960 24 A2 936  
11 A2 897 34 A2 863  
12 A2 735 -16 A2 751  
13 A2 341 -80 A2 421  
14 B1 925   B1   760 reassinged to mode 15
15 B1 721 -39 B1 760 696 questionable
16 B1 336 -34 B1 370  
17 B2 3087 12 B2 3075  
18 B2 3069 26 B2 3043  
19 B2 1546 -19 B2 1565  
20 B2 1379 -65 B2 1444  
21 B2 1259 20 B2 1239  
22 B2 1045 -7 B2 1052  
23 B2 1007 -2 B2 1009  
24 B2 601 -63 B2 664  
The calculated vibrational frequencies were scaled by 0.9857

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.