return to home page

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

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

mPW1PW91/6-31G**

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3056 38 Ag 3018  
2 Ag 2938 8 Ag 2930  
3 Ag 1760 41 Ag 1719  
4 Ag 1395 -29 Ag 1424  
5 Ag 1344 -22 Ag 1366  
6 Ag 1245 -29 Ag 1274  
7 Ag 969 -35 Ag 1004  
8 Ag 669 -16 Ag 685  
9 Ag 506 -108 Ag 614  
10 Ag 345 -24 Ag 369  
11 Au 3008 18 Au 2990  
12 Au 1400 -21 Au 1421  
13 Au 913 -198 Au 1111  
14 Au 333 -6 Au 339  
15 Au 103        
16 Au 49 1 Au 48  
17 Bg 3008 30 Bg 2978  
18 Bg 1405 -19 Bg 1424  
19 Bg 1020 -89 Bg 1109  
20 Bg 596 58 Bg 538  
21 Bg 94 -146 Bg 240  
22 Bu 3056 45 Bu 3011  
23 Bu 2938 12 Bu 2926  
24 Bu 1757 39 Bu 1718  
25 Bu 1396 -25 Bu 1421  
26 Bu 1331 -22 Bu 1353  
27 Bu 1091 -20 Bu 1111  
28 Bu 882 -45 Bu 927  
29 Bu 516 -18 Bu 534  
30 Bu 226 -24 Bu 250  
The calculated vibrational frequencies were scaled by 0.9515

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.