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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 2974 -44 Ag 3018  
2 A 2920 -10 Ag 2930  
3 A 2846 1127 Ag 1719  
4 A 1590 166 Ag 1424  
5 A 1419 53 Ag 1366  
6 A 1398 124 Ag 1274  
7 A 1313 309 Ag 1004  
8 A 1137 452 Ag 685  
9 A 951 337 Ag 614  
10 A 918 549 Ag 369  
11 A 609 -2381 Au 2990  
12 A 508 -913 Au 1421  
13 A 371 -740 Au 1111  
14 A 351 12 Au 339  
15 A 106        
16 A 62 14 Au 48  
17 B 2974 -4 Bg 2978  
18 B 2920 1496 Bg 1424  
19 B 2846 1737 Bg 1109  
20 B 1599 1061 Bg 538  
21 B 1419 1179 Bg 240  
22 B 1402 -1609 Bu 3011  
23 B 1312 -1614 Bu 2926  
24 B 1060 -658 Bu 1718  
25 B 1023 -398 Bu 1421  
26 B 870 -483 Bu 1353  
27 B 622 -489 Bu 1111  
28 B 488 -439 Bu 927  
29 B 266 -268 Bu 534  
30 B 68 -182 Bu 250  
The calculated vibrational frequencies were scaled by 0.9535

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.