return to home page

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

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

MP2/6-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3056 38 Ag 3018  
2 Ag 2942 12 Ag 2930  
3 Ag 1662 -57 Ag 1719  
4 Ag 1435 11 Ag 1424  
5 Ag 1370 4 Ag 1366  
6 Ag 1268 -6 Ag 1274  
7 Ag 983 -21 Ag 1004  
8 Ag 672 -13 Ag 685  
9 Ag 506 -108 Ag 614  
10 Ag 350 -19 Ag 369  
11 Au 3021 31 Au 2990  
12 Au 1436 15 Au 1421  
13 Au 940 -171 Au 1111  
14 Au 330 -9 Au 339  
15 Au 119        
16 Au 58 10 Au 48  
17 Bg 3021 43 Bg 2978  
18 Bg 1439 15 Bg 1424  
19 Bg 1029 -80 Bg 1109  
20 Bg 589 51 Bg 538  
21 Bg 120 -120 Bg 240  
22 Bu 3056 45 Bu 3011  
23 Bu 2942 16 Bu 2926  
24 Bu 1658 -60 Bu 1718  
25 Bu 1436 15 Bu 1421  
26 Bu 1361 8 Bu 1353  
27 Bu 1106 -5 Bu 1111  
28 Bu 894 -33 Bu 927  
29 Bu 514 -20 Bu 534  
30 Bu 231 -19 Bu 250  
The calculated vibrational frequencies were scaled by 0.943

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.