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

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

QCISD/3-21G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3044 26 Ag 3018  
2 Ag 2955 25 Ag 2930  
3 Ag 1658 -61 Ag 1719  
4 Ag 1489 65 Ag 1424  
5 Ag 1415 49 Ag 1366  
6 Ag 1218 -56 Ag 1274  
7 Ag 998 -6 Ag 1004  
8 Ag 635 -50 Ag 685  
9 Ag 526 -88 Ag 614  
10 Ag 358 -11 Ag 369  
11 Au 3013 23 Au 2990  
12 Au 1503 82 Au 1421  
13 Au 1003 -108 Au 1111  
14 Au 372 33 Au 339  
15 Au 119        
16 Au 72 24 Au 48  
17 Bg 3013 35 Bg 2978  
18 Bg 1506 82 Bg 1424  
19 Bg 1085 -24 Bg 1109  
20 Bg 646 108 Bg 538  
21 Bg 97 -143 Bg 240  
22 Bu 3044 33 Bu 3011  
23 Bu 2955 29 Bu 2926  
24 Bu 1637 -81 Bu 1718  
25 Bu 1491 70 Bu 1421  
26 Bu 1415 62 Bu 1353  
27 Bu 1119 8 Bu 1111  
28 Bu 876 -51 Bu 927  
29 Bu 514 -20 Bu 534  
30 Bu 236 -14 Bu 250  
The calculated vibrational frequencies were scaled by 0.9692

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.