return to home page

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

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

PBEPBE/6-31G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3085 67 Ag 3018  
2 Ag 2957 27 Ag 2930  
3 Ag 1629 -90 Ag 1719  
4 Ag 1429 5 Ag 1424  
5 Ag 1370 4 Ag 1366  
6 Ag 1251 -23 Ag 1274  
7 Ag 991 -13 Ag 1004  
8 Ag 670 -15 Ag 685  
9 Ag 511 -103 Ag 614  
10 Ag 357 -12 Ag 369  
11 Au 3024 34 Au 2990  
12 Au 1433 12 Au 1421  
13 Au 946 -165 Au 1111  
14 Au 342 3 Au 339  
15 Au 101        
16 Au 52 4 Au 48  
17 Bg 3024 46 Bg 2978  
18 Bg 1439 15 Bg 1424  
19 Bg 1040 -69 Bg 1109  
20 Bg 613 75 Bg 538  
21 Bg 86 -154 Bg 240  
22 Bu 3085 74 Bu 3011  
23 Bu 2957 31 Bu 2926  
24 Bu 1632 -86 Bu 1718  
25 Bu 1433 12 Bu 1421  
26 Bu 1368 15 Bu 1353  
27 Bu 1120 9 Bu 1111  
28 Bu 909 -18 Bu 927  
29 Bu 524 -10 Bu 534  
30 Bu 234 -16 Bu 250  
The calculated vibrational frequencies were scaled by 0.9862

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.