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

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

MP2/6-31+G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3067 49 Ag 3018  
2 Ag 2945 15 Ag 2930  
3 Ag 1633 -86 Ag 1719  
4 Ag 1415 -9 Ag 1424  
5 Ag 1354 -12 Ag 1366  
6 Ag 1252 -22 Ag 1274  
7 Ag 976 -28 Ag 1004  
8 Ag 669 -16 Ag 685  
9 Ag 499 -115 Ag 614  
10 Ag 346 -23 Ag 369  
11 Au 3029 39 Au 2990  
12 Au 1414 -7 Au 1421  
13 Au 923 -188 Au 1111  
14 Au 326 -13 Au 339  
15 Au 105        
16 Au 36 -12 Au 48  
17 Bg 3029 51 Bg 2978  
18 Bg 1417 -7 Bg 1424  
19 Bg 1008 -101 Bg 1109  
20 Bg 573 35 Bg 538  
21 Bg 104 -136 Bg 240  
22 Bu 3068 57 Bu 3011  
23 Bu 2945 19 Bu 2926  
24 Bu 1632 -86 Bu 1718  
25 Bu 1416 -5 Bu 1421  
26 Bu 1345 -8 Bu 1353  
27 Bu 1096 -15 Bu 1111  
28 Bu 888 -39 Bu 927  
29 Bu 513 -21 Bu 534  
30 Bu 227 -23 Bu 250  
The calculated vibrational frequencies were scaled by 0.9406

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.