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

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

CISD/3-21G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3031 13 Ag 3018  
2 Ag 2944 14 Ag 2930  
3 Ag 1714 -5 Ag 1719  
4 Ag 1475 51 Ag 1424  
5 Ag 1412 46 Ag 1366  
6 Ag 1225 -49 Ag 1274  
7 Ag 1004 0 Ag 1004  
8 Ag 645 -40 Ag 685  
9 Ag 530 -84 Ag 614  
10 Ag 360 -9 Ag 369  
11 Au 3000 10 Au 2990  
12 Au 1488 67 Au 1421  
13 Au 999 -112 Au 1111  
14 Au 378 39 Au 339  
15 Au 119        
16 Au 72 24 Au 48  
17 Bg 3000 22 Bg 2978  
18 Bg 1491 67 Bg 1424  
19 Bg 1089 -20 Bg 1109  
20 Bg 652 114 Bg 538  
21 Bg 99 -141 Bg 240  
22 Bu 3031 20 Bu 3011  
23 Bu 2943 17 Bu 2926  
24 Bu 1696 -22 Bu 1718  
25 Bu 1477 56 Bu 1421  
26 Bu 1412 59 Bu 1353  
27 Bu 1120 9 Bu 1111  
28 Bu 885 -42 Bu 927  
29 Bu 518 -16 Bu 534  
30 Bu 239 -11 Bu 250  
The calculated vibrational frequencies were scaled by 0.9344

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.