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 CCSD/CEP-31G
Calculated values were scaled by 0.9431.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H4 Ethylene 7 B2g 940 718 -221 1.308
SO2 Sulfur dioxide 1 A1 1151 774 -377 1.488
SO2 Sulfur dioxide 2 A1 518 347 -171 1.494
SO2 Sulfur dioxide 3 B2 1362 822 -540 1.657
NH3 Ammonia 2 torsion A1 950 737 -213 1.288
H2O Water 1 A1 3657 2406 -1251 1.520
H2O Water 3 B2 3756 2532 -1224 1.483
Cl2 Chlorine diatomic 1 Σg 554 375 -179 1.478
IBr Iodine monobromide 1 Σ 267 193 -74 1.381
ICl Iodine monochloride 1 Σ 381 278 -103 1.369
BF Boron monofluoride 1 Σ 1379 1050 -328 1.313
Na2 Sodium diatomic 1 Σg 158 113 -44 1.392