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 0.9548.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 171 58 0.660
CH3CONH2 Acetamide 20 A 259 143 -116 1.807
CH3OH Methyl alcohol 12 A" 200 332 132 0.603
C2H6O2S Dimethyl sulfone 20 B1 262 207 -55 1.263
C2H4+ Ethylene cation 4 Au 84 -478 -562 -0.176
CHONH2 formamide 12 A" 289 136 -153 2.123
CH3COCl Acetyl Chloride 15 A" 166 129 -37 1.291
C2F6 hexafluoroethane 4 A1u 68 41 -27 1.645
C3F8 perfluoropropane 13 A2 276 197 -79 1.404
CH3COOCH3 methyl acetate 26 A" 136 58 -78 2.357
CH3COOCH3 methyl acetate 27 A" 110 39 -71 2.808
C3H6O 2-Propen-1-ol 24 A 188 112 -76 1.676
C4H8S Thiophene, tetrahydro- 5 A 1464 2949 1485 0.496
C4H8S Thiophene, tetrahydro- 6 A 1441 2949 1508 0.489
C4H8S Thiophene, tetrahydro- 7 A 1321 2933 1612 0.450
C4H8S Thiophene, tetrahydro- 8 A 1276 2933 1657 0.435
C4H8S Thiophene, tetrahydro- 12 A 888 1417 529 0.627
C4H8S Thiophene, tetrahydro- 13 A 829 1307 478 0.634
C4H8S Thiophene, tetrahydro- 14 A 822 1280 458 0.642
C4H8S Thiophene, tetrahydro- 15 A 678 1254 576 0.541
C4H8S Thiophene, tetrahydro- 16 A 472 1231 759 0.383
C4H8S Thiophene, tetrahydro- 17 A 290 1189 899 0.244
CH3CH2CHO Propanal 24 A" 135 95 -40 1.427
C5H8 Cyclopentene 18 A' 254 149 -105 1.710
C6F6 hexafluorobenzene 7 B2g 719 506 -213 1.420
C4H6O2 2,3-Butanedione 21 Bg 240 113 -127 2.116
C6H4 Benzyne 24 B2 472 371 -101 1.272
C5H12 Propane, 2,2-dimethyl- 12 T1 203 296 93 0.687
C2H3NO3 Oxamic acid 3 A' 2600 3466 866 0.750
C2H3NO3 Oxamic acid 15 A' 328 253 -75 1.296
C2H3NO3 Oxamic acid 21 A" 162 71 -91 2.273
C3H6O Oxetane 18 B1 90 10 -80 9.163
C3O2 Carbon suboxide 7 Πu 61 113 52 0.539
C5H8 1,4-Pentadiene 16 A 137 282 145 0.486
CH3SSCH3 Disulfide, dimethyl 13 A 117 93 -24 1.260
C6H6 Benzvalene 10 A1 996 746 -250 1.335
H2CS- thioformaldehyde anion 4 B1 450 -146 -596 -3.072
SiF2+ Silicon difluoride cation 2 A1 350 277 -73 1.262
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 212 68 0.680
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 343 -113 1.329
CH3 Methyl radical 2 A2" 606 421 -186 1.441
CH2OH Hydroxymethyl radical 9 A 234 432 198 0.541
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 863 -273 1.316
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 145 -119 1.818
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 98 -260 3.644
HCCN cyanomethylene 5 Π 129 -256 -384 -0.504
CHCl2 dichloromethyl radical 4 A' 190 297 107 0.639
C4H6 Methylenecyclopropane 17 B1 360 281 -79 1.280
N2O3 Dinitrogen trioxide 9 A" 63 145 82 0.434
C3O Tricarbon monoxide 5 Π 109 173 64 0.630
C3 carbon trimer 3 Πu 63 139 76 0.455
H3O+ hydronium cation 2 A1 954 752 -202 1.268
ZnH2 Zinc hydride 3 Πu 633 482 -151 1.313
ClOO chloroperoxy radical 2 A' 414 302 -112 1.372
ClOO chloroperoxy radical 3 A' 201 116 -86 1.741
OPCl Phosphorus oxychloride 2 A' 308 489 181 0.630
OPCl Phosphorus oxychloride 3 A' 492 295 -197 1.667
H2OH2O water dimer 7 A' 143 211 68 0.677
H2OH2O water dimer 11 A" 108 164 56 0.659
H2OH2O water dimer 12 A" 88 67 -21 1.317
H2POH Phosphinous acid 9 A" 375 255 -120 1.470
ZnCH3 Zinc monomethyl 6 E 315 590 275 0.534
ZnCN Zinc monocyanide 3 Π 212 68 -144 3.104