return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) 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

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 ROHF/cc-pVTZ
Calculated values were scaled by 0.901.

Species Name mode Symmetry Experiment Theory difference ratio
C2H4+ Ethylene cation 4 Au 84 426 342 0.197
H2CS- thioformaldehyde anion 4 B1 450 -210 -660 -2.144
C2H Ethynyl radical 3 Π 372 676 305 0.550
CH3 Methyl radical 2 A2" 606 157 -450 3.868
CH2OH Hydroxymethyl radical 8 A 482 796 314 0.605
CH2OH Hydroxymethyl radical 9 A 234 360 126 0.650
ClCO carbonyl monochloride 3 A' 335 210 -125 1.593
HCCN cyanomethylene 2 Σ 1735 2197 462 0.790
HCCN cyanomethylene 5 Π 129 -863 -992 -0.149
C2H3+ vinyl cation 2 A1 2217 2869 652 0.773
CHCl2 dichloromethyl radical 4 A' 190 287 97 0.661
N3 azide radical 3 Πu 457 659 202 0.693
AlO Aluminum monoxide 1 Σ 979 706 -274 1.388
ClOO chloroperoxy radical 1 A' 1443 1079 -364 1.337
ClOO chloroperoxy radical 2 A' 414 730 316 0.567
ClOO chloroperoxy radical 3 A' 201 438 237 0.460