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

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

MP4/6-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3042 24 Ag 3018  
2 Ag 2934 4 Ag 2930  
3 Ag 1664 -55 Ag 1719  
4 Ag 1437 13 Ag 1424  
5 Ag 1370 4 Ag 1366  
6 Ag 1264 -10 Ag 1274  
7 Ag 982 -22 Ag 1004  
8 Ag 665 -20 Ag 685  
9 Ag 501 -113 Ag 614  
10 Ag 349 -20 Ag 369  
11 Au 3006 16 Au 2990  
12 Au 1439 18 Au 1421  
13 Au 941 -170 Au 1111  
14 Au 327 -12 Au 339  
15 Au 113        
16 Au 53 5 Au 48  
17 Bg 3007 29 Bg 2978  
18 Bg 1441 17 Bg 1424  
19 Bg 1029 -80 Bg 1109  
20 Bg 587 49 Bg 538  
21 Bg 112 -128 Bg 240  
22 Bu 3042 31 Bu 3011  
23 Bu 2934 8 Bu 2926  
24 Bu 1648 -70 Bu 1718  
25 Bu 1438 17 Bu 1421  
26 Bu 1363 10 Bu 1353  
27 Bu 1106 -5 Bu 1111  
28 Bu 889 -38 Bu 927  
29 Bu 512 -22 Bu 534  
30 Bu 228 -22 Bu 250  
The calculated vibrational frequencies were scaled by 0.9548

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.