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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(TQ)/6-31G
Calculated values were scaled by 1.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H2 Acetylene 4 Πg 612 360 -252 1.702
CO2 Carbon dioxide 3 Πu 667 528 -139 1.262
SO2 Sulfur dioxide 1 A1 1151 834 -317 1.380
SO2 Sulfur dioxide 2 A1 518 373 -144 1.387
SO2 Sulfur dioxide 3 B2 1362 952 -410 1.431
NH3 Ammonia 2 torsion A1 950 780 -170 1.218
F2 Fluorine diatomic 1 Σg 894 716 -178 1.249
O2 Oxygen diatomic 1 Σg 1556 1253 -303 1.242
Cl2 Chlorine diatomic 1 Σg 554 386 -168 1.437