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

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

HF/CEP-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3010 -8 Ag 3018  
2 Ag 2916 -14 Ag 2930  
3 Ag 1816 97 Ag 1719  
4 Ag 1428 4 Ag 1424  
5 Ag 1395 29 Ag 1366  
6 Ag 1277 3 Ag 1274  
7 Ag 996 -8 Ag 1004  
8 Ag 673 -12 Ag 685  
9 Ag 508 -106 Ag 614  
10 Ag 339 -30 Ag 369  
11 Au 2983 -7 Au 2990  
12 Au 1433 12 Au 1421  
13 Au 959 -152 Au 1111  
14 Au 352 13 Au 339  
15 Au 120        
16 Au 50 2 Au 48  
17 Bg 2983 5 Bg 2978  
18 Bg 1436 12 Bg 1424  
19 Bg 1059 -50 Bg 1109  
20 Bg 607 69 Bg 538  
21 Bg 120 -120 Bg 240  
22 Bu 3010 -1 Bu 3011  
23 Bu 2916 -10 Bu 2926  
24 Bu 1786 68 Bu 1718  
25 Bu 1427 6 Bu 1421  
26 Bu 1379 26 Bu 1353  
27 Bu 1101 -10 Bu 1111  
28 Bu 892 -35 Bu 927  
29 Bu 516 -18 Bu 534  
30 Bu 222 -28 Bu 250  
The calculated vibrational frequencies were scaled by 0.898

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.