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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 3050 32 Ag 3018  
2 Ag 2940 10 Ag 2930  
3 Ag 1739 20 Ag 1719  
4 Ag 1410 -14 Ag 1424  
5 Ag 1350 -16 Ag 1366  
6 Ag 1238 -36 Ag 1274  
7 Ag 975 -29 Ag 1004  
8 Ag 660 -25 Ag 685  
9 Ag 503 -111 Ag 614  
10 Ag 347 -22 Ag 369  
11 Au 3000 10 Au 2990  
12 Au 1415 -6 Au 1421  
13 Au 924 -187 Au 1111  
14 Au 334 -5 Au 339  
15 Au 107        
16 Au 50 2 Au 48  
17 Bg 3000 22 Bg 2978  
18 Bg 1419 -5 Bg 1424  
19 Bg 1027 -82 Bg 1109  
20 Bg 598 60 Bg 538  
21 Bg 101 -139 Bg 240  
22 Bu 3050 39 Bu 3011  
23 Bu 2940 14 Bu 2926  
24 Bu 1739 21 Bu 1718  
25 Bu 1411 -10 Bu 1421  
26 Bu 1342 -11 Bu 1353  
27 Bu 1094 -17 Bu 1111  
28 Bu 878 -49 Bu 927  
29 Bu 520 -14 Bu 534  
30 Bu 229 -21 Bu 250  
The calculated vibrational frequencies were scaled by 0.9608

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.