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

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

B3LYP/CEP-31G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3080 62 Ag 3018  
2 Ag 2959 29 Ag 2930  
3 Ag 1612 -107 Ag 1719  
4 Ag 1422 -2 Ag 1424  
5 Ag 1377 11 Ag 1366  
6 Ag 1258 -16 Ag 1274  
7 Ag 990 -14 Ag 1004  
8 Ag 662 -23 Ag 685  
9 Ag 504 -110 Ag 614  
10 Ag 342 -27 Ag 369  
11 Au 3033 43 Au 2990  
12 Au 1423 2 Au 1421  
13 Au 961 -150 Au 1111  
14 Au 353 14 Au 339  
15 Au 98        
16 Au 50 2 Au 48  
17 Bg 3032 54 Bg 2978  
18 Bg 1427 3 Bg 1424  
19 Bg 1048 -61 Bg 1109  
20 Bg 606 68 Bg 538  
21 Bg 88 -152 Bg 240  
22 Bu 3080 69 Bu 3011  
23 Bu 2959 33 Bu 2926  
24 Bu 1605 -113 Bu 1718  
25 Bu 1425 4 Bu 1421  
26 Bu 1373 20 Bu 1353  
27 Bu 1109 -2 Bu 1111  
28 Bu 907 -20 Bu 927  
29 Bu 515 -19 Bu 534  
30 Bu 224 -26 Bu 250  
The calculated vibrational frequencies were scaled by 0.9684

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.