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

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

MP2/STO-3G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 Ag 3104 86 Ag 3018  
2 Ag 2937 7 Ag 2930  
3 Ag 1527 -192 Ag 1719  
4 Ag 1477 53 Ag 1424  
5 Ag 1378 12 Ag 1366  
6 Ag 1170 -104 Ag 1274  
7 Ag 952 -52 Ag 1004  
8 Ag 619 -66 Ag 685  
9 Ag 462 -152 Ag 614  
10 Ag 291 -78 Ag 369  
11 Au 3092 102 Au 2990  
12 Au 1487 66 Au 1421  
13 Au 951 -160 Au 1111  
14 Au 297 -42 Au 339  
15 Au 87        
16 Au 42 -6 Au 48  
17 Bg 3092 114 Bg 2978  
18 Bg 1489 65 Bg 1424  
19 Bg 1000 -109 Bg 1109  
20 Bg 536 -2 Bg 538  
21 Bg 79 -161 Bg 240  
22 Bu 3104 93 Bu 3011  
23 Bu 2937 11 Bu 2926  
24 Bu 1510 -208 Bu 1718  
25 Bu 1474 53 Bu 1421  
26 Bu 1376 23 Bu 1353  
27 Bu 1042 -69 Bu 1111  
28 Bu 870 -57 Bu 927  
29 Bu 454 -80 Bu 534  
30 Bu 171 -79 Bu 250  
The calculated vibrational frequencies were scaled by 0.8719

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.