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 B3LYP/6-311+G(3df,2p)
Calculated values were scaled by 0.967.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 181 68 0.624
CH3COOH Acetic acid 18 A" 93 72 -21 1.295
CH3COCl Acetyl Chloride 15 A" 166 130 -36 1.276
C5H8 Cyclopentene 18 A' 254 135 -119 1.886
C5H12 Propane, 2,2-dimethyl- 12 T1 203 298 95 0.681
C2H3NO3 Oxamic acid 3 A' 2600 3468 868 0.750
C2H3NO3 Oxamic acid 15 A' 328 260 -68 1.260
C2H3NO3 Oxamic acid 17 A" 815 648 -167 1.258
C2H3NO3 Oxamic acid 21 A" 162 60 -102 2.692
C3O2 Carbon suboxide 7 Πu 61 29 -32 2.078
C5H8 1,4-Pentadiene 16 A 137 293 156 0.467
NaOH sodium hydroxide 3 Π 300 210 -90 1.430
C2H Ethynyl radical 3 Π 372 294 -78 1.265
C4H9N Cyclobutylamine 21 A' 174 133 -41 1.306
CH2OH Hydroxymethyl radical 9 A 234 396 162 0.591
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 866 -270 1.312
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 148 -116 1.779
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 101 -257 3.559
C4H6 Methylenecyclopropane 17 B1 360 284 -76 1.266
PCl5 Phosphorus pentachloride 2 A1' 370 258 -112 1.435
C3 carbon trimer 3 Πu 63 91 27 0.698
MgOH magnesium hydroxide 3 Π 188 117 -71 1.609
ClOO chloroperoxy radical 2 A' 414 316 -98 1.311
ClOO chloroperoxy radical 3 A' 201 109 -93 1.853