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

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

MP2/6-311G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3053 35 Ag 3018  
2 Ag 2937 7 Ag 2930  
3 Ag 1670 -49 Ag 1719  
4 Ag 1405 -19 Ag 1424  
5 Ag 1342 -24 Ag 1366  
6 Ag 1245 -29 Ag 1274  
7 Ag 970 -34 Ag 1004  
8 Ag 669 -16 Ag 685  
9 Ag 507 -107 Ag 614  
10 Ag 348 -21 Ag 369  
11 Au 3017 27 Au 2990  
12 Au 1410 -11 Au 1421  
13 Au 920 -191 Au 1111  
14 Au 331 -8 Au 339  
15 Au 120        
16 Au 53 5 Au 48  
17 Bg 3017 39 Bg 2978  
18 Bg 1413 -11 Bg 1424  
19 Bg 1021 -88 Bg 1109  
20 Bg 588 50 Bg 538  
21 Bg 120 -120 Bg 240  
22 Bu 3054 43 Bu 3011  
23 Bu 2937 11 Bu 2926  
24 Bu 1670 -48 Bu 1718  
25 Bu 1406 -15 Bu 1421  
26 Bu 1331 -22 Bu 1353  
27 Bu 1093 -18 Bu 1111  
28 Bu 882 -45 Bu 927  
29 Bu 515 -19 Bu 534  
30 Bu 230 -20 Bu 250  
The calculated vibrational frequencies were scaled by 0.9502

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.