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 QCISD(T)/3-21G
Calculated values were scaled by 0.9537.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C2H2 Acetylene 4 Πg 612 459 -153 1.334
CO2 Carbon dioxide 3 Πu 667 520 -147 1.283
C2H4F2 1,2-difluoroethane 18 Bu 295 221 -74 1.336
CaO Calcium monoxide 1 Σ 723 528 -195 1.368
CS carbon monosulfide 1 Σ 1272 1010 -262 1.260
HO2 Hydroperoxy radical 3 A' 1098 827 -270 1.327
SO2 Sulfur dioxide 1 A1 1151 753 -398 1.528
SO2 Sulfur dioxide 2 A1 518 372 -146 1.393
SO2 Sulfur dioxide 3 B2 1362 841 -521 1.619
O2 Oxygen diatomic 1 Σg 1556 1215 -342 1.281
Cl2 Chlorine diatomic 1 Σg 554 380 -174 1.458
IBr Iodine monobromide 1 Σ 267 202 -65 1.322
ICl Iodine monochloride 1 Σ 381 285 -97 1.340
NO Nitric oxide 1 Σ 1876 1421 -455 1.320