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

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

B3PW91/6-31G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3059 41 Ag 3018  
2 Ag 2942 12 Ag 2930  
3 Ag 1751 32 Ag 1719  
4 Ag 1398 -26 Ag 1424  
5 Ag 1343 -23 Ag 1366  
6 Ag 1241 -33 Ag 1274  
7 Ag 970 -34 Ag 1004  
8 Ag 666 -19 Ag 685  
9 Ag 504 -110 Ag 614  
10 Ag 346 -23 Ag 369  
11 Au 3011 21 Au 2990  
12 Au 1403 -18 Au 1421  
13 Au 913 -198 Au 1111  
14 Au 333 -6 Au 339  
15 Au 103        
16 Au 48 -0 Au 48  
17 Bg 3011 33 Bg 2978  
18 Bg 1408 -16 Bg 1424  
19 Bg 1020 -89 Bg 1109  
20 Bg 596 58 Bg 538  
21 Bg 95 -145 Bg 240  
22 Bu 3060 49 Bu 3011  
23 Bu 2942 16 Bu 2926  
24 Bu 1750 32 Bu 1718  
25 Bu 1399 -22 Bu 1421  
26 Bu 1332 -21 Bu 1353  
27 Bu 1091 -20 Bu 1111  
28 Bu 880 -47 Bu 927  
29 Bu 517 -17 Bu 534  
30 Bu 226 -24 Bu 250  
The calculated vibrational frequencies were scaled by 0.9584

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.