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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 QCISD(T)/CEP-31G
Calculated values were scaled by 0.9537.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H4 Ethylene 7 B2g 940 694 -246 1.354
CO2 Carbon dioxide 3 Πu 667 528 -139 1.264
SO2 Sulfur dioxide 1 A1 1151 675 -477 1.707
SO2 Sulfur dioxide 2 A1 518 315 -203 1.643
SO2 Sulfur dioxide 3 B2 1362 525 -837 2.595
NH3 Ammonia 2 torsion A1 950 748 -202 1.270
F2 Fluorine diatomic 1 Σg 894 676 -218 1.322
Cl2 Chlorine diatomic 1 Σg 554 372 -182 1.490
IBr Iodine monobromide 1 Σ 267 193 -74 1.380
ICl Iodine monochloride 1 Σ 381 278 -103 1.371
BF Boron monofluoride 1 Σ 1379 1046 -333 1.318
Na2 Sodium diatomic 1 Σg 158 115 -43 1.376