return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Bad vibrational frequency predictions

19 02 11 15 45

Calculated frequencies that differ from experiment by more than 400 cm-1 or have a ratio with experiment outside of 0.7 to 1.2 are listed

Calculated vibrational frequencies ("theory" in table) are calculated at QCISD(T)/SDD
Calculated values were scaled by 0.9537.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H4 Ethylene 7 B2g 940 744 -195 1.262
SO2 Sulfur dioxide 1 A1 1151 720 -431 1.599
SO2 Sulfur dioxide 2 A1 518 349 -169 1.483
SO2 Sulfur dioxide 3 B2 1362 749 -613 1.819
NH3 Ammonia 2 torsion A1 950 716 -234 1.327
F2 Fluorine diatomic 1 Σg 894 669 -225 1.336
O2 Oxygen diatomic 1 Σg 1556 1227 -329 1.268
Cl2 Chlorine diatomic 1 Σg 554 384 -171 1.444
IBr Iodine monobromide 1 Σ 267 188 -79 1.420
ICl Iodine monochloride 1 Σ 381 283 -98 1.347
BF Boron monofluoride 1 Σ 1379 1044 -334 1.320