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 B1B95/6-31G*
Calculated values were scaled by 0.9493.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 170 57 0.663
CH3OH Methyl alcohol 12 A" 200 330 130 0.607
CH3CONH2 Acetamide 20 A 259 165 -94 1.566
C2H4+ Ethylene cation 4 Au 84 -447 -531 -0.188
CHONH2 formamide 12 A" 289 135 -154 2.136
CH3COCl Acetyl Chloride 15 A" 166 129 -37 1.282
C2F6 hexafluoroethane 4 A1u 68 41 -27 1.648
C3F8 perfluoropropane 13 A2 276 195 -81 1.412
CH3COOCH3 methyl acetate 26 A" 136 80 -56 1.704
CH3COOCH3 methyl acetate 27 A" 110 49 -61 2.254
C3H6O 2-Propen-1-ol 24 A 188 112 -76 1.685
C4H8S Thiophene, tetrahydro- 5 A 1464 2946 1482 0.497
C4H8S Thiophene, tetrahydro- 6 A 1441 2946 1505 0.489
C4H8S Thiophene, tetrahydro- 7 A 1321 2929 1608 0.451
C4H8S Thiophene, tetrahydro- 8 A 1276 2929 1653 0.436
C4H8S Thiophene, tetrahydro- 11 A 1023 1431 408 0.715
C4H8S Thiophene, tetrahydro- 12 A 888 1430 542 0.621
C4H8S Thiophene, tetrahydro- 13 A 829 1314 485 0.631
C4H8S Thiophene, tetrahydro- 14 A 822 1288 466 0.638
C4H8S Thiophene, tetrahydro- 15 A 678 1263 585 0.537
C4H8S Thiophene, tetrahydro- 16 A 472 1238 766 0.381
C4H8S Thiophene, tetrahydro- 17 A 290 1195 905 0.243
CH3CH2CHO Propanal 24 A" 135 104 -31 1.293
C5H8 Cyclopentene 18 A' 254 149 -105 1.704
C6F6 hexafluorobenzene 7 B2g 719 497 -222 1.448
C4H6O2 2,3-Butanedione 21 Bg 240 102 -138 2.353
C6H4 Benzyne 24 B2 472 370 -102 1.276
C5H12 Propane, 2,2-dimethyl- 12 T1 203 295 92 0.688
C2H3NO3 Oxamic acid 3 A' 2600 3450 850 0.754
C2H3NO3 Oxamic acid 15 A' 328 252 -76 1.303
C2H3NO3 Oxamic acid 21 A" 162 70 -92 2.329
C3H6O Oxetane 18 B1 90 10 -80 9.216
C3O2 Carbon suboxide 7 Πu 61 112 51 0.547
C5H8 1,4-Pentadiene 16 A 137 282 145 0.486
C6H6 Benzvalene 10 A1 996 742 -254 1.343
H2CS- thioformaldehyde anion 4 B1 450 -146 -596 -3.090
SiF2+ Silicon difluoride cation 2 A1 350 276 -74 1.269
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 210 66 0.684
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 341 -115 1.337
CH3 Methyl radical 2 A2" 606 401 -206 1.513
HCCN cyanomethylene 5 Π 129 -254 -383 -0.507
CH2OH Hydroxymethyl radical 9 A 234 439 205 0.533
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 98 -260 3.672
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 145 -119 1.824
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 863 -273 1.316
CHCl2 dichloromethyl radical 4 A' 190 296 106 0.643
C4H6 Methylenecyclopropane 17 B1 360 281 -79 1.282
N2O3 Dinitrogen trioxide 9 A" 63 145 82 0.436
C3 carbon trimer 3 Πu 63 138 75 0.458
ZnH2 Zinc hydride 3 Πu 633 491 -142 1.288
C3O Tricarbon monoxide 5 Π 109 172 63 0.634
OPCl Phosphorus oxychloride 2 A' 308 486 178 0.634
OPCl Phosphorus oxychloride 3 A' 492 294 -198 1.676
H2POH Phosphinous acid 9 A" 375 254 -121 1.478
ZnCH3 Zinc monomethyl 6 E 315 585 270 0.538
ZnCN Zinc monocyanide 3 Π 212 68 -144 3.122
H2OH2O water dimer 7 A' 143 211 68 0.679
H2OH2O water dimer 11 A" 108 164 56 0.658
H2OH2O water dimer 12 A" 88 69 -19 1.274