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

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

MP2/6-31G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3052 34 Ag 3018  
2 Ag 2943 13 Ag 2930  
3 Ag 1544 -175 Ag 1719  
4 Ag 1467 43 Ag 1424  
5 Ag 1409 43 Ag 1366  
6 Ag 1273 -1 Ag 1274  
7 Ag 1005 1 Ag 1004  
8 Ag 668 -17 Ag 685  
9 Ag 514 -100 Ag 614  
10 Ag 357 -12 Ag 369  
11 Au 3019 29 Au 2990  
12 Au 1473 52 Au 1421  
13 Au 988 -123 Au 1111  
14 Au 343 4 Au 339  
15 Au 116        
16 Au 62 14 Au 48  
17 Bg 3019 41 Bg 2978  
18 Bg 1475 51 Bg 1424  
19 Bg 1060 -49 Bg 1109  
20 Bg 597 59 Bg 538  
21 Bg 116 -124 Bg 240  
22 Bu 3052 41 Bu 3011  
23 Bu 2943 17 Bu 2926  
24 Bu 1537 -181 Bu 1718  
25 Bu 1471 50 Bu 1421  
26 Bu 1409 56 Bu 1353  
27 Bu 1133 22 Bu 1111  
28 Bu 914 -13 Bu 927  
29 Bu 526 -8 Bu 534  
30 Bu 235 -15 Bu 250  
The calculated vibrational frequencies were scaled by 0.9568

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.