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

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

B3LYP/CEP-121G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3058 40 Ag 3018  
2 Ag 2934 4 Ag 2930  
3 Ag 1617 -102 Ag 1719  
4 Ag 1440 16 Ag 1424  
5 Ag 1389 23 Ag 1366  
6 Ag 1257 -17 Ag 1274  
7 Ag 998 -6 Ag 1004  
8 Ag 661 -24 Ag 685  
9 Ag 508 -106 Ag 614  
10 Ag 346 -23 Ag 369  
11 Au 3008 18 Au 2990  
12 Au 1439 18 Au 1421  
13 Au 968 -143 Au 1111  
14 Au 346 7 Au 339  
15 Au 101        
16 Au 36 -12 Au 48  
17 Bg 3008 30 Bg 2978  
18 Bg 1444 20 Bg 1424  
19 Bg 1052 -57 Bg 1109  
20 Bg 605 67 Bg 538  
21 Bg 90 -150 Bg 240  
22 Bu 3059 48 Bu 3011  
23 Bu 2934 8 Bu 2926  
24 Bu 1609 -109 Bu 1718  
25 Bu 1444 23 Bu 1421  
26 Bu 1387 34 Bu 1353  
27 Bu 1116 5 Bu 1111  
28 Bu 907 -20 Bu 927  
29 Bu 519 -15 Bu 534  
30 Bu 227 -23 Bu 250  
The calculated vibrational frequencies were scaled by 0.9745

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.