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

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

MP2/CEP-121G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3049 31 Ag 3018  
2 Ag 2917 -13 Ag 2930  
3 Ag 1520 -199 Ag 1719  
4 Ag 1452 28 Ag 1424  
5 Ag 1412 46 Ag 1366  
6 Ag 1276 2 Ag 1274  
7 Ag 1005 1 Ag 1004  
8 Ag 663 -22 Ag 685  
9 Ag 510 -104 Ag 614  
10 Ag 346 -23 Ag 369  
11 Au 3014 24 Au 2990  
12 Au 1449 28 Au 1421  
13 Au 982 -129 Au 1111  
14 Au 334 -5 Au 339  
15 Au 108        
16 Au 48 -0 Au 48  
17 Bg 3014 36 Bg 2978  
18 Bg 1451 27 Bg 1424  
19 Bg 1060 -49 Bg 1109  
20 Bg 577 39 Bg 538  
21 Bg 107 -133 Bg 240  
22 Bu 3049 38 Bu 3011  
23 Bu 2917 -9 Bu 2926  
24 Bu 1510 -208 Bu 1718  
25 Bu 1457 36 Bu 1421  
26 Bu 1412 59 Bu 1353  
27 Bu 1129 18 Bu 1111  
28 Bu 911 -16 Bu 927  
29 Bu 515 -19 Bu 534  
30 Bu 225 -25 Bu 250  
The calculated vibrational frequencies were scaled by 0.976

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.