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 CCSD(T)/6-31G
Calculated values were scaled by 0.9431.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H2 Acetylene 4 Πg 612 345 -267 1.774
CO2 Carbon dioxide 3 Πu 667 494 -173 1.349
CaO Calcium monoxide 1 Σ 723 404 -319 1.790
SO2 Sulfur dioxide 1 A1 1151 735 -417 1.567
SO2 Sulfur dioxide 2 A1 518 341 -177 1.518
SO2 Sulfur dioxide 3 B2 1362 788 -574 1.729
NH3 Ammonia 2 torsion A1 950 736 -214 1.291
F2 Fluorine diatomic 1 Σg 894 686 -208 1.303
O2 Oxygen diatomic 1 Σg 1556 1199 -358 1.299
Cl2 Chlorine diatomic 1 Σg 554 368 -186 1.505