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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)/STO-3G
Calculated values were scaled by 1.

Species Name mode int rot Symmetry Experiment Theory difference ratio
CH2CHCH3 Propene 1 A' 3090 3499 409 0.883
CH2CHCH3 Propene 2 A' 3013 3436 423 0.877
CH2CHCH3 Propene 3 A' 2991 3399 408 0.880
CH2CHCH3 Propene 4 A' 2954 3355 401 0.880
CH2CHCH3 Propene 15 A" 2954 3411 457 0.866
NH3 Ammonia 2 torsion A1 950 1488 538 0.638
H2O Water 2 A1 1595 2038 443 0.783
Na2 Sodium diatomic 1 Σg 158 483 326 0.326
SO2 Sulfur dioxide 1 A1 1151 823 -328 1.399
SO2 Sulfur dioxide 2 A1 518 375 -143 1.381
SO2 Sulfur dioxide 3 B2 1362 247 -1114 5.506
C3H5 Allyl radical 13 B2 3105 3510 405 0.885
CO2 Carbon dioxide 3 Πu 667 453 -214 1.473
C3H6 Cyclopropane 6 A2" 3103 3504 401 0.885
C3H6 Cyclopropane 12 E" 3082 3498 416 0.881
C2H4 Ethylene 8 B2u 3105 3507 402 0.885
C2H4 Ethylene 10 B3g 3086 3494 408 0.883
C2H6 Ethane 7 Eg 2969 3430 461 0.866
C2H6 Ethane 10 Eu 2985 3442 457 0.867
CH4 Methane 3 T2 3019 3478 459 0.868
H2CO Formaldehyde 5 B2 2843 3294 451 0.863