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

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

PBEPBE/3-21G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A 3090 72 Ag 3018  
2 A 3035 105 Ag 2930  
3 A 2958 1239 Ag 1719  
4 A 1653 229 Ag 1424  
5 A 1474 108 Ag 1366  
6 A 1453 179 Ag 1274  
7 A 1365 361 Ag 1004  
8 A 1182 497 Ag 685  
9 A 988 374 Ag 614  
10 A 954 585 Ag 369  
11 A 633 -2357 Au 2990  
12 A 528 -893 Au 1421  
13 A 385 -726 Au 1111  
14 A 365 26 Au 339  
15 A 110        
16 A 64 16 Au 48  
17 B 3090 112 Bg 2978  
18 B 3034 1610 Bg 1424  
19 B 2958 1849 Bg 1109  
20 B 1661 1123 Bg 538  
21 B 1474 1234 Bg 240  
22 B 1457 -1554 Bu 3011  
23 B 1364 -1562 Bu 2926  
24 B 1102 -616 Bu 1718  
25 B 1063 -358 Bu 1421  
26 B 904 -449 Bu 1353  
27 B 646 -465 Bu 1111  
28 B 507 -420 Bu 927  
29 B 277 -257 Bu 534  
30 B 70 -180 Bu 250  
The calculated vibrational frequencies were scaled by 0.9909

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.