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

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

mPW1PW91/STO-3G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3116 98 Ag 3018  
2 Ag 2946 16 Ag 2930  
3 Ag 1636 -83 Ag 1719  
4 Ag 1460 36 Ag 1424  
5 Ag 1355 -11 Ag 1366  
6 Ag 1157 -117 Ag 1274  
7 Ag 948 -56 Ag 1004  
8 Ag 620 -65 Ag 685  
9 Ag 464 -150 Ag 614  
10 Ag 296 -73 Ag 369  
11 Au 3092 102 Au 2990  
12 Au 1459 38 Au 1421  
13 Au 931 -180 Au 1111  
14 Au 302 -37 Au 339  
15 Au 81        
16 Au 26 -22 Au 48  
17 Bg 3092 114 Bg 2978  
18 Bg 1461 37 Bg 1424  
19 Bg 989 -120 Bg 1109  
20 Bg 548 10 Bg 538  
21 Bg 62 -178 Bg 240  
22 Bu 3116 105 Bu 3011  
23 Bu 2946 20 Bu 2926  
24 Bu 1634 -84 Bu 1718  
25 Bu 1461 40 Bu 1421  
26 Bu 1354 1 Bu 1353  
27 Bu 1039 -72 Bu 1111  
28 Bu 867 -60 Bu 927  
29 Bu 460 -74 Bu 534  
30 Bu 176 -74 Bu 250  
The calculated vibrational frequencies were scaled by 0.8789

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.