return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) Standard Reference Database 101 National Institute of Standards and Technology
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Bad vibrational frequency predictions

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 B3LYP/aug-cc-pVQZ
Calculated values were scaled by 0.9689.

Species Name mode Symmetry Experiment Theory difference ratio
C2H4+ Ethylene cation 4 Au 84 -486 -570 -0.173
H2CS- thioformaldehyde anion 4 B1 450 304 -146 1.482
CH2CHSH Ethenethiol 5 A' 1603 3041 1438 0.527
NaOH sodium hydroxide 3 Π 300 166 -134 1.803
CH2OH Hydroxymethyl radical 9 A 234 396 162 0.591
HCCN cyanomethylene 5 Π 129 -214 -343 -0.602
C2H3+ vinyl cation 2 A1 2217 2901 684 0.764
OPCl Phosphorus oxychloride 2 A' 308 466 158 0.661
OPCl Phosphorus oxychloride 3 A' 492 290 -202 1.695
H2POH Phosphinous acid 9 A" 375 254 -121 1.475