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

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

HF/6-31G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 2991 -27 Ag 3018  
2 Ag 2895 -35 Ag 2930  
3 Ag 1842 123 Ag 1719  
4 Ag 1432 8 Ag 1424  
5 Ag 1397 31 Ag 1366  
6 Ag 1284 10 Ag 1274  
7 Ag 1004 0 Ag 1004  
8 Ag 677 -8 Ag 685  
9 Ag 520 -94 Ag 614  
10 Ag 350 -19 Ag 369  
11 Au 2956 -34 Au 2990  
12 Au 1438 17 Au 1421  
13 Au 961 -150 Au 1111  
14 Au 353 14 Au 339  
15 Au 119        
16 Au 51 3 Au 48  
17 Bg 2956 -22 Bg 2978  
18 Bg 1441 17 Bg 1424  
19 Bg 1064 -45 Bg 1109  
20 Bg 614 76 Bg 538  
21 Bg 119 -121 Bg 240  
22 Bu 2991 -20 Bu 3011  
23 Bu 2894 -32 Bu 2926  
24 Bu 1818 100 Bu 1718  
25 Bu 1431 10 Bu 1421  
26 Bu 1384 31 Bu 1353  
27 Bu 1114 3 Bu 1111  
28 Bu 897 -30 Bu 927  
29 Bu 530 -4 Bu 534  
30 Bu 231 -19 Bu 250  
The calculated vibrational frequencies were scaled by 0.9026

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.