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

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

LSDA/6-31+G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3077 59 Ag 3018  
2 Ag 2943 13 Ag 2930  
3 Ag 1743 24 Ag 1719  
4 Ag 1354 -70 Ag 1424  
5 Ag 1331 -35 Ag 1366  
6 Ag 1236 -38 Ag 1274  
7 Ag 951 -53 Ag 1004  
8 Ag 687 2 Ag 685  
9 Ag 505 -109 Ag 614  
10 Ag 350 -19 Ag 369  
11 Au 3012 22 Au 2990  
12 Au 1350 -71 Au 1421  
13 Au 875 -236 Au 1111  
14 Au 326 -13 Au 339  
15 Au 92        
16 Au 36 -12 Au 48  
17 Bg 3012 34 Bg 2978  
18 Bg 1358 -66 Bg 1424  
19 Bg 996 -113 Bg 1109  
20 Bg 586 48 Bg 538  
21 Bg 76 -164 Bg 240  
22 Bu 3078 66 Bu 3011  
23 Bu 2943 17 Bu 2926  
24 Bu 1750 32 Bu 1718  
25 Bu 1355 -66 Bu 1421  
26 Bu 1298 -55 Bu 1353  
27 Bu 1097 -14 Bu 1111  
28 Bu 888 -39 Bu 927  
29 Bu 516 -18 Bu 534  
30 Bu 230 -20 Bu 250  
The calculated vibrational frequencies were scaled by 0.9839

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.