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

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

MP2=FULL/6-311G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3055 37 Ag 3018  
2 Ag 2938 8 Ag 2930  
3 Ag 1671 -48 Ag 1719  
4 Ag 1401 -23 Ag 1424  
5 Ag 1342 -24 Ag 1366  
6 Ag 1246 -28 Ag 1274  
7 Ag 969 -35 Ag 1004  
8 Ag 670 -15 Ag 685  
9 Ag 507 -107 Ag 614  
10 Ag 348 -21 Ag 369  
11 Au 3018 28 Au 2990  
12 Au 1406 -15 Au 1421  
13 Au 919 -192 Au 1111  
14 Au 332 -7 Au 339  
15 Au 121        
16 Au 54 6 Au 48  
17 Bg 3018 40 Bg 2978  
18 Bg 1410 -14 Bg 1424  
19 Bg 1021 -88 Bg 1109  
20 Bg 589 51 Bg 538  
21 Bg 121 -119 Bg 240  
22 Bu 3055 44 Bu 3011  
23 Bu 2938 12 Bu 2926  
24 Bu 1671 -47 Bu 1718  
25 Bu 1402 -19 Bu 1421  
26 Bu 1329 -24 Bu 1353  
27 Bu 1093 -18 Bu 1111  
28 Bu 883 -44 Bu 927  
29 Bu 515 -19 Bu 534  
30 Bu 231 -19 Bu 250  
The calculated vibrational frequencies were scaled by 0.9486

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.