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

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

B3PW91/6-31+G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3061 43 Ag 3018  
2 Ag 2944 14 Ag 2930  
3 Ag 1737 18 Ag 1719  
4 Ag 1395 -29 Ag 1424  
5 Ag 1342 -24 Ag 1366  
6 Ag 1237 -37 Ag 1274  
7 Ag 971 -33 Ag 1004  
8 Ag 667 -18 Ag 685  
9 Ag 501 -113 Ag 614  
10 Ag 346 -23 Ag 369  
11 Au 3012 22 Au 2990  
12 Au 1398 -23 Au 1421  
13 Au 914 -197 Au 1111  
14 Au 336 -3 Au 339  
15 Au 104        
16 Au 44 -4 Au 48  
17 Bg 3012 34 Bg 2978  
18 Bg 1403 -21 Bg 1424  
19 Bg 1018 -91 Bg 1109  
20 Bg 593 55 Bg 538  
21 Bg 101 -139 Bg 240  
22 Bu 3062 51 Bu 3011  
23 Bu 2944 18 Bu 2926  
24 Bu 1736 18 Bu 1718  
25 Bu 1396 -25 Bu 1421  
26 Bu 1332 -21 Bu 1353  
27 Bu 1091 -20 Bu 1111  
28 Bu 884 -43 Bu 927  
29 Bu 521 -13 Bu 534  
30 Bu 226 -24 Bu 250  
The calculated vibrational frequencies were scaled by 0.9601

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.