return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Calculated > Vibrations > Bad Calculations > Bad vib. Calc. vs exp. OR Resources > Bad Calculations > Vibrations > Bad vib. Calc. vs exp.

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=FULL/6-311G**
Calculated values were scaled by 1.

Species Name mode int rot Symmetry Experiment Theory difference ratio
CH2I2 Diiodomethane 3 A1 704 492 -212 1.431
CH2I2 Diiodomethane 4 A1 285 122 -163 2.343
CH2I2 Diiodomethane 7 B1 896 738 -158 1.214
CH2I2 Diiodomethane 9 B2 738 600 -138 1.230
H2O Water 1 A1 3657 2402 -1255 1.522
H2O Water 3 B2 3756 2542 -1214 1.477