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

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

MP2=FULL/6-31G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3060 42 Ag 3018  
2 Ag 2939 9 Ag 2930  
3 Ag 1653 -66 Ag 1719  
4 Ag 1418 -6 Ag 1424  
5 Ag 1354 -12 Ag 1366  
6 Ag 1254 -20 Ag 1274  
7 Ag 971 -33 Ag 1004  
8 Ag 668 -17 Ag 685  
9 Ag 502 -112 Ag 614  
10 Ag 345 -24 Ag 369  
11 Au 3024 34 Au 2990  
12 Au 1424 3 Au 1421  
13 Au 927 -184 Au 1111  
14 Au 328 -11 Au 339  
15 Au 113        
16 Au 58 10 Au 48  
17 Bg 3024 46 Bg 2978  
18 Bg 1427 3 Bg 1424  
19 Bg 1019 -90 Bg 1109  
20 Bg 584 46 Bg 538  
21 Bg 112 -128 Bg 240  
22 Bu 3060 49 Bu 3011  
23 Bu 2939 13 Bu 2926  
24 Bu 1650 -68 Bu 1718  
25 Bu 1419 -2 Bu 1421  
26 Bu 1344 -9 Bu 1353  
27 Bu 1095 -16 Bu 1111  
28 Bu 883 -44 Bu 927  
29 Bu 508 -26 Bu 534  
30 Bu 227 -23 Bu 250  
The calculated vibrational frequencies were scaled by 0.9344

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.