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

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

B3PW91/STO-3G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3113 95 Ag 3018  
2 Ag 2944 14 Ag 2930  
3 Ag 1624 -95 Ag 1719  
4 Ag 1461 37 Ag 1424  
5 Ag 1354 -12 Ag 1366  
6 Ag 1146 -128 Ag 1274  
7 Ag 943 -61 Ag 1004  
8 Ag 613 -72 Ag 685  
9 Ag 461 -153 Ag 614  
10 Ag 295 -74 Ag 369  
11 Au 3089 99 Au 2990  
12 Au 1461 40 Au 1421  
13 Au 929 -182 Au 1111  
14 Au 300 -39 Au 339  
15 Au 80        
16 Au 28 -20 Au 48  
17 Bg 3089 111 Bg 2978  
18 Bg 1463 39 Bg 1424  
19 Bg 986 -123 Bg 1109  
20 Bg 545 7 Bg 538  
21 Bg 62 -178 Bg 240  
22 Bu 3113 102 Bu 3011  
23 Bu 2944 18 Bu 2926  
24 Bu 1624 -94 Bu 1718  
25 Bu 1462 41 Bu 1421  
26 Bu 1352 -1 Bu 1353  
27 Bu 1036 -75 Bu 1111  
28 Bu 861 -66 Bu 927  
29 Bu 460 -74 Bu 534  
30 Bu 176 -74 Bu 250  
The calculated vibrational frequencies were scaled by 0.885

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.