return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) 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
C4H8S Thiophene, tetrahydro- 5 A 1464 2953 1489 0.496
C4H8S Thiophene, tetrahydro- 6 A 1441 2953 1512 0.488
C4H8S Thiophene, tetrahydro- 7 A 1321 2939 1618 0.449
C4H8S Thiophene, tetrahydro- 8 A 1276 2938 1662 0.434
C4H8S Thiophene, tetrahydro- 12 A 888 1414 526 0.628
C4H8S Thiophene, tetrahydro- 13 A 829 1296 467 0.639
C4H8S Thiophene, tetrahydro- 14 A 822 1275 453 0.644
C4H8S Thiophene, tetrahydro- 15 A 678 1243 565 0.546
C4H8S Thiophene, tetrahydro- 16 A 472 1229 757 0.384
C4H8S Thiophene, tetrahydro- 17 A 290 1187 897 0.244
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
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 185 -42 1.229
CH3ONO Methyl nitrite 15 A" 186 153 -33 1.213
C6H6 Benzvalene 10 A1 996 740 -256 1.346
NaOH sodium hydroxide 3 Π 300 94 -206 3.193
H2CS- thioformaldehyde anion 4 B1 450 299 -151 1.506
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 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
B2H6 Diborane 14 B2u 369 304 -64 1.211
OClO- Chlorine dioxide anion 2 A1 418 344 -74 1.213
Mg2 Magnesium diatomic 1 Σg 51 102 51 0.500
OPCl Phosphorus oxychloride 3 A' 492 286 -206 1.719
OPCl Phosphorus oxychloride 2 A' 308 475 167 0.648
ZnCN Zinc monocyanide 3 Π 212 167 -45 1.268