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

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

MP2/CEP-31G*

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3067 49 Ag 3018  
2 Ag 2943 13 Ag 2930  
3 Ag 1652 -67 Ag 1719  
4 Ag 1409 -15 Ag 1424  
5 Ag 1366 -0 Ag 1366  
6 Ag 1261 -13 Ag 1274  
7 Ag 976 -28 Ag 1004  
8 Ag 670 -15 Ag 685  
9 Ag 496 -118 Ag 614  
10 Ag 341 -28 Ag 369  
11 Au 3036 46 Au 2990  
12 Au 1413 -8 Au 1421  
13 Au 941 -170 Au 1111  
14 Au 333 -6 Au 339  
15 Au 117        
16 Au 61 13 Au 48  
17 Bg 3036 58 Bg 2978  
18 Bg 1416 -8 Bg 1424  
19 Bg 1029 -80 Bg 1109  
20 Bg 587 49 Bg 538  
21 Bg 119 -121 Bg 240  
22 Bu 3067 56 Bu 3011  
23 Bu 2944 18 Bu 2926  
24 Bu 1646 -73 Bu 1718  
25 Bu 1410 -11 Bu 1421  
26 Bu 1352 -1 Bu 1353  
27 Bu 1095 -16 Bu 1111  
28 Bu 893 -34 Bu 927  
29 Bu 505 -29 Bu 534  
30 Bu 223 -27 Bu 250  
The calculated vibrational frequencies were scaled by 0.9494

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.