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

Compare vibrational frequencies in CCCBDB for C4H6O2 (2,3-Butanedione)

B3LYPultrafine/6-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3041 23 Ag 3018  
2 Ag 2936 6 Ag 2930  
3 Ag 1735 16 Ag 1719  
4 Ag 1423 -1 Ag 1424  
5 Ag 1358 -8 Ag 1366  
6 Ag 1239 -35 Ag 1274  
7 Ag 980 -24 Ag 1004  
8 Ag 658 -27 Ag 685  
9 Ag 502 -112 Ag 614  
10 Ag 347 -22 Ag 369  
11 Au 2992 2 Au 2990  
12 Au 1426 5 Au 1421  
13 Au 931 -180 Au 1111  
14 Au 333 -6 Au 339  
15 Au 108        
16 Au 53 5 Au 48  
17 Bg 2992 14 Bg 2978  
18 Bg 1430 6 Bg 1424  
19 Bg 1033 -76 Bg 1109  
20 Bg 598 60 Bg 538  
21 Bg 105 -135 Bg 240  
22 Bu 3042 31 Bu 3011  
23 Bu 2936 10 Bu 2926  
24 Bu 1734 16 Bu 1718  
25 Bu 1424 3 Bu 1421  
26 Bu 1352 -1 Bu 1353  
27 Bu 1096 -15 Bu 1111  
28 Bu 880 -47 Bu 927  
29 Bu 519 -15 Bu 534  
30 Bu 229 -21 Bu 250  
The calculated vibrational frequencies were scaled by 0.958

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.