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

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

B3LYP/6-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3049 31 Ag 3018  
2 Ag 2943 13 Ag 2930  
3 Ag 1739 20 Ag 1719  
4 Ag 1426 2 Ag 1424  
5 Ag 1363 -3 Ag 1366  
6 Ag 1242 -32 Ag 1274  
7 Ag 983 -21 Ag 1004  
8 Ag 661 -24 Ag 685  
9 Ag 503 -111 Ag 614  
10 Ag 349 -20 Ag 369  
11 Au 3000 10 Au 2990  
12 Au 1430 9 Au 1421  
13 Au 934 -177 Au 1111  
14 Au 334 -5 Au 339  
15 Au 113        
16 Au 54 6 Au 48  
17 Bg 3000 22 Bg 2978  
18 Bg 1434 10 Bg 1424  
19 Bg 1036 -73 Bg 1109  
20 Bg 601 63 Bg 538  
21 Bg 109 -131 Bg 240  
22 Bu 3049 38 Bu 3011  
23 Bu 2943 17 Bu 2926  
24 Bu 1738 20 Bu 1718  
25 Bu 1427 6 Bu 1421  
26 Bu 1357 4 Bu 1353  
27 Bu 1099 -12 Bu 1111  
28 Bu 882 -45 Bu 927  
29 Bu 520 -14 Bu 534  
30 Bu 230 -20 Bu 250  
The calculated vibrational frequencies were scaled by 0.9603

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.