return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) Standard Reference Database 101 National Institute of Standards and Technology
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Bad vibrational frequency predictions

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(T)/6-31G**
Calculated values were scaled by 0.9485.

Species Name mode Symmetry Experiment Theory difference ratio
CH3OH Methyl alcohol 12 A" 200 325 125 0.616
C2H2 Acetylene 4 Πg 612 371 -241 1.652
CH3CCH propyne 10 E 328 246 -82 1.332
CF2CCl2 difluorodichloroethylene 7 B1 1327 522 -805 2.544
CF2CCl2 difluorodichloroethylene 8 B1 989 306 -683 3.227
CF2CCl2 difluorodichloroethylene 11 B2 564 436 -128 1.295
CF2CCl2 difluorodichloroethylene 12 B2 323 179 -144 1.805
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 318 -891 3.797
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 396 -137 1.347
C3H6O Oxetane 18 B1 90 -74 -164 -1.216
NaOH sodium hydroxide 3 Π 300 120 -180 2.500
C2H Ethynyl radical 3 Π 372 277 -95 1.343
CH3 Methyl radical 2 A2" 606 398 -208 1.522
CH2OH Hydroxymethyl radical 8 A 482 710 228 0.679
CH2OH Hydroxymethyl radical 9 A 234 425 191 0.550
CH3CO Acetyl radical 4 A' 1420 3035 1615 0.468
CHCl2 dichloromethyl radical 4 A' 190 295 105 0.644
H2OH2O water dimer 11 A" 108 157 49 0.688
Mg2 Magnesium diatomic 1 Σg 51 279 228 0.183
CH3BO Borane, methyloxo- 7 E 897 1436 539 0.625