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

Compare vibrational frequencies in CCCBDB for C4H6 (Cyclobutene)

QCISD/3-21G

Frequency in cm-1
  Calculated   Experimental
Mode Number Symmetry Frequency diff Symmetry Frequency Comment
1 A1 3121 61 A1 3060  
2 A1 2976 41 A1 2935  
3 A1 1540 -30 A1 1570  
4 A1 1497 47 A1 1450  
5 A1 1193 -83 A1 1276  
6 A1 1096 -90 A1 1186  
7 A1 925 -188 A1 1113  
8 A1 789 -97 A1 886  
9 A2 3016 61 A2 2955  
10 A2 1159 -117 A2 1276  
11 A2 1012 -69 A2 1081  
12 A2 883 33 A2 850  
13 A2 297 -28 A2 325  
14 B1 3032 77 B1 2955  
15 B1 1097 23 B1 1074  
16 B1 856 10 B1 846  
17 B1 650 15 B1 635  
18 B2 3085 38 B2 3047  
19 B2 2968 52 B2 2916  
20 B2 1491 64 B2 1427  
21 B2 1278 -16 B2 1294  
22 B2 1224 10 B2 1214  
23 B2 859 -29 B2 888  
24 B2 805 65 B2 740  
The calculated vibrational frequencies were scaled by 0.9692

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.