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 MP4/6-31G
Calculated values were scaled by 0.9438.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H2 Acetylene 4 Πg 612 332 -280 1.843
HNCO Isocyanic acid 6 A" 656 494 -162 1.329
CO2 Carbon dioxide 1 Σg 1333 1046 -287 1.274
CO2 Carbon dioxide 3 Πu 667 473 -194 1.411
CO Carbon monoxide 1 Σ 2143 1583 -560 1.354
C4H6O Cyclobutanone 13 A2 909 685 -224 1.326
CS carbon monosulfide 1 Σ 1272 806 -466 1.578
SO2 Sulfur dioxide 1 A1 1151 863 -288 1.334
SO2 Sulfur dioxide 2 A1 518 364 -153 1.421
NH3 Ammonia 2 torsion A1 950 729 -221 1.303
O2 Oxygen diatomic 1 Σg 1556 991 -566 1.571
Cl2 Chlorine diatomic 1 Σg 554 382 -172 1.450
NO Nitric oxide 1 Σ 1876 3559 1683 0.527
Si2 Silicon diatomic 1 Σg 507 390 -117 1.299