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 PBEPBE/6-311+G(3df,2p)
Calculated values were scaled by 0.9918.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 182 69 0.622
CH3CONH2 Acetamide 20 A 259 191 -67 1.352
CH3COOH Acetic acid 18 A" 93 62 -31 1.511
C2H6O2S Dimethyl sulfone 20 B1 262 208 -54 1.262
CH3COCl Acetyl Chloride 15 A" 166 129 -37 1.285
C2H2O2 Ethanedial 7 Au 127 105 -22 1.213
C5H8 Cyclopentene 18 A' 254 142 -112 1.783
C4H4N2 Pyridazine 13 A2 421 342 -79 1.231
C5H12 Propane, 2,2-dimethyl- 12 T1 203 306 103 0.664
C2H3NO3 Oxamic acid 3 A' 2600 3470 870 0.749
C2H3NO3 Oxamic acid 15 A' 328 256 -72 1.281
C2H3NO3 Oxamic acid 16 A" 984 793 -191 1.242
C2H3NO3 Oxamic acid 17 A" 815 657 -158 1.241
C2H3NO3 Oxamic acid 21 A" 162 63 -99 2.573
C3O2 Carbon suboxide 7 Πu 61 48 -13 1.261
C5H8 1,4-Pentadiene 16 A 137 290 153 0.472
C5H8 1,4-Pentadiene 17 A 102 84 -18 1.213
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 185 -42 1.229
CH3ONO Methyl nitrite 15 A" 186 153 -33 1.213
NaOH sodium hydroxide 3 Π 300 94 -206 3.193
CH2OH Hydroxymethyl radical 9 A 234 400 166 0.585
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 870 -266 1.306
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 152 -112 1.734
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 102 -256 3.510
C4H6 Methylenecyclopropane 17 B1 360 275 -85 1.309
BrF3 Bromine trifluoride 3 A1 242 200 -42 1.210
PCl5 Phosphorus pentachloride 2 A1' 370 266 -104 1.393
PCl5 Phosphorus pentachloride 7 E' 100 81 -19 1.235
N2O4 Dinitrogen tetroxide 9 B2u 265 187 -78 1.416
ClOO chloroperoxy radical 3 A' 201 293 92 0.687
Mg2 Magnesium diatomic 1 Σg 51 102 51 0.500