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

Compare vibrational frequencies in CCCBDB for CH3COOH (Acetic acid)

MP2/3-21G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A' 3342 -241 A' 3583  
2 A' 3072 21 A' 3051  
3 A' 2974 30 A' 2944  
4 A' 1673 -115 A' 1788  
5 A' 1503 73 A' 1430  
6 A' 1411 29 A' 1382  
7 A' 1326 62 A' 1264  
8 A' 1132 -50 A' 1182  
9 A' 964 -25 A' 989  
10 A' 792 -55 A' 847  
11 A' 541 -116 A' 657  
12 A' 390   A'   questionable (581 listed)
13 A" 3041 45 A" 2996  
14 A" 1510 80 A" 1430  
15 A" 1080 32 A" 1048  
16 A" 632 -10 A" 642  
17 A" 529 -5 A" 534  
18 A" 107 14 A" 93  
The calculated vibrational frequencies were scaled by 0.9545

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.