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

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

CCD/3-21G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3014 -4 Ag 3018  
2 Ag 2927 -3 Ag 2930  
3 Ag 1670 -49 Ag 1719  
4 Ag 1477 53 Ag 1424  
5 Ag 1403 37 Ag 1366  
6 Ag 1218 -56 Ag 1274  
7 Ag 995 -9 Ag 1004  
8 Ag 640 -45 Ag 685  
9 Ag 529 -85 Ag 614  
10 Ag 358 -11 Ag 369  
11 Au 2985 -5 Au 2990  
12 Au 1488 67 Au 1421  
13 Au 997 -114 Au 1111  
14 Au 373 34 Au 339  
15 Au 122        
16 Au 78 30 Au 48  
17 Bg 2985 7 Bg 2978  
18 Bg 1491 67 Bg 1424  
19 Bg 1079 -30 Bg 1109  
20 Bg 643 105 Bg 538  
21 Bg 105 -135 Bg 240  
22 Bu 3014 3 Bu 3011  
23 Bu 2927 1 Bu 2926  
24 Bu 1659 -59 Bu 1718  
25 Bu 1478 57 Bu 1421  
26 Bu 1403 50 Bu 1353  
27 Bu 1111 0 Bu 1111  
28 Bu 879 -48 Bu 927  
29 Bu 515 -19 Bu 534  
30 Bu 235 -15 Bu 250  
The calculated vibrational frequencies were scaled by 0.9565

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.