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 QCISD/6-31+G**
Calculated values were scaled by 0.9454.

Species Name mode Symmetry Experiment Theory difference ratio
CH3COOH Acetic acid 18 A" 93 69 -24 1.352
CH3OH Methyl alcohol 12 A" 200 304 104 0.659
C6H6 Benzene 8 B2g 703 404 -299 1.739
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 307 93 0.696
C2H4+ Ethylene cation 4 Au 84 -221 -305 -0.381
C2H2 Acetylene 4 Πg 612 443 -169 1.381
CH3CCH propyne 10 E 328 251 -77 1.309
CHONH2 formamide 12 A" 289 -168 -457 -1.715
CH3COCl Acetyl Chloride 15 A" 166 121 -45 1.377
C3F8 perfluoropropane 13 A2 276 216 -60 1.279
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 57 -18 1.326
CH3COOCH3 methyl acetate 27 A" 110 45 -65 2.454
C9H8 Indene 40 A" 690 472 -218 1.461
C9H8 Indene 41 A" 549 432 -117 1.271
C6H5CHO benzaldehyde 32 A" 688 440 -248 1.563
C3H6O 2-Propen-1-ol 24 A 188 105 -83 1.797
C6H5Cl chlorobenzene 18 B1 685 445 -239 1.537
C5H12 Pentane 23 A2 131 97 -34 1.356
CH2C(CH3)CH3 1-Propene, 2-methyl- 15 A2 193 149 -44 1.293
C2Cl4 Tetrachloroethylene 7 B2g 512 296 -216 1.728
C5H8 Cyclopentene 18 A' 254 164 -90 1.550
C3H4N2 1H-Imidazole 21 A" 539 423 -116 1.273
C2H3N3 1H-1,2,4-Triazole 18 A" 640 481 -159 1.330
C4H4N2 Pyridazine 13 A2 421 328 -93 1.282
NH2CN cyanamide 5 A' 408 629 221 0.649
C4H6O2 2,3-Butanedione 16 Au 48 35 -13 1.391
C4H6O2 2,3-Butanedione 21 Bg 240 108 -132 2.229
C6H5F Fluorobenzene 18 B1 685 482 -203 1.421
C3H6O Oxetane 18 B1 90 -81 -171 -1.109
C3O2 Carbon suboxide 7 Πu 61 119 58 0.511
HCNO fulminic acid 5 Π 224 -64 -288 -3.529
C6H4F2 1,4-difluorobenzene 16 B2g 692 462 -230 1.499
C5H8 1,4-Pentadiene 16 A 137 284 147 0.483
HCCBr bromoacetylene 5 Π 295 424 129 0.696
HCCCl Chloroacetylene 5 Π 326 216 -110 1.508
CH3SSCH3 Disulfide, dimethyl 13 A 117 91 -26 1.285
C6H8 1,4-Cyclohexadiene 19 B1u 108 75 -33 1.443
C6H8 1,4-Cyclohexadiene 23 B2g 403 291 -112 1.386
C6H6 Benzvalene 10 A1 996 745 -251 1.338
C6H8 (E)-hexa-1,3,5-triene 24 Bg 217 139 -78 1.563
H2CS- thioformaldehyde anion 4 B1 450 232 -218 1.944
C4N2 2-Butynedinitrile 6 Πg 504 291 -213 1.729
C4N2 2-Butynedinitrile 7 Πg 263 149 -114 1.766
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 213 69 0.678
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 320 -136 1.425
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 93 -78 1.832
C6H5O phenoxy radical 19 B1 472 366 -106 1.290
CH3 Methyl radical 2 A2" 606 458 -148 1.324
CH2OH Hydroxymethyl radical 9 A 234 420 186 0.557
HCCN cyanomethylene 5 Π 129 -518 -647 -0.249
C6H6 Trimethylenecycopropane 10 A2" 212 161 -51 1.313
C6H6 Trimethylenecycopropane 20 E" 340 255 -85 1.335
CHCl2 dichloromethyl radical 4 A' 190 296 106 0.642
C4H6 Methylenecyclopropane 17 B1 360 249 -111 1.448
C2Cl2 dichloroacetylene 4 Πg 333 60 -273 5.508
SiO2 silicon dioxide 3 Πu 273 211 -62 1.293
O3 Ozone 3 B2 1042 812 -230 1.283
OClO- Chlorine dioxide anion 2 A1 418 317 -101 1.317
N2O3 Dinitrogen trioxide 9 A" 63 120 57 0.525
Li2O dilithium oxide 3 Πu 112 53 -58 2.098
C3 carbon trimer 3 Πu 63 -109 -172 -0.584
TiO Titanium monoxide 1 Σ 1009 678 -331 1.489
C4 Carbon tetramer 4 Πg 323 190 -133 1.704
Cl3- trichloride anion 2 Σu 327 194 -133 1.685
CaS Calcium sulfide 1 Σ 462 361 -101 1.281
OPCl Phosphorus oxychloride 2 A' 308 477 169 0.645
OPCl Phosphorus oxychloride 3 A' 492 294 -198 1.671
H2OH2O water dimer 8 A' 103 156 53 0.660
H2OH2O water dimer 11 A" 108 161 53 0.671
H2OH2O water dimer 12 A" 88 133 45 0.661
F3- trifluoride anion 2 Σu 550 306 -244 1.799
H2POH Phosphinous acid 9 A" 375 260 -115 1.444
Mg2 Magnesium diatomic 1 Σg 51 15 -37 3.516
Al2 Aluminum diatomic 1 Σg 286 432 146 0.661
ZnCH3 Zinc monomethyl 6 E 315 594 279 0.530