return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) 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 MP4/6-311G*
Calculated values were scaled by 0.959.

Species Name mode Symmetry Experiment Theory difference ratio
CH3OH Methyl alcohol 12 A" 200 350 150 0.571
C2H2 Acetylene 4 Πg 612 311 -301 1.970
BeO beryllium oxide 1 Σ 1457 779 -679 1.871
MgO magnesium oxide 1 Σ 785 1135 350 0.692
LiOH lithium hydroxide 3 Π 257 394 138 0.651
NaOH sodium hydroxide 3 Π 300 184 -116 1.631
CN Cyano radical 1 Σ 2069 2576 508 0.803
C2H Ethynyl radical 2 Σ 1841 2282 442 0.806
C2H Ethynyl radical 3 Π 372 710 339 0.523
CH3 Methyl radical 2 A2" 606 419 -188 1.449
CH2OH Hydroxymethyl radical 8 A 482 700 218 0.688
CH2OH Hydroxymethyl radical 9 A 234 462 228 0.506
SiO Silicon monoxide 1 Σ 1242 971 -271 1.279
NO Nitric oxide 1 Σ 1904 3434 1530 0.554
FO Oxygen monofluoride 1 Σ 1053 2404 1351 0.438
PO Phosphorus monoxide 1 Σ 1233 5730 4497 0.215
Mg2 Magnesium diatomic 1 Σg 51 30 -21 1.713