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

Compare vibrational frequencies in CCCBDB for C4H4N2 (Pyridazine)

BLYP/3-21G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3128 65 A1 3063  
2 A1 3089 46 A1 3043  
3 A1 1532 -40 A1 1572  
4 A1 1386 -28 A1 1414  
5 A1 1182 -101 A1 1283  
6 A1 1085 -75 A1 1160  
7 A1 1001 -62 A1 1063  
8 A1 786 -178 A1 964  
9 A1 665 46 A1 619  
10 A2 1011 75 A2 936  
11 A2 928 65 A2 863  
12 A2 748 -3 A2 751  
13 A2 346 -75 A2 421  
14 B1 968   B1   760 reassinged to mode 15
15 B1 746 -14 B1 760 696 questionable
16 B1 352 -18 B1 370  
17 B2 3111 36 B2 3075  
18 B2 3086 43 B2 3043  
19 B2 1489 -76 B2 1565  
20 B2 1400 -44 B2 1444  
21 B2 1254 15 B2 1239  
22 B2 1045 -7 B2 1052  
23 B2 996 -13 B2 1009  
24 B2 616 -48 B2 664  
The calculated vibrational frequencies were scaled by 0.9945

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.