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/3-21G*
Calculated values were scaled by 0.9431.

Species Name mode int rot Symmetry Experiment Theory difference ratio
H2O Water 1 A1 3657 2331 -1326 1.569
H2O Water 3 B2 3756 2504 -1252 1.500
NO Nitric oxide 1 Σ 1876 1402 -474 1.338
CaOH Calcium monohydroxide 3 Π 353 504 151 0.700
Na2 Sodium diatomic 1 Σg 158 118 -39 1.331