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 MP2/6-31G*
Calculated values were scaled by 0.943.

Species Name mode Symmetry Experiment Theory difference ratio
CH3SeH Methane selenol 12 A" 145 211 66 0.688
C3H4O2 β–Propiolactone 21 A" 113 162 49 0.699
CH3OH Methyl alcohol 12 A" 200 336 136 0.595
CH3COCH3 Acetone 12 A2 77 56 -21 1.367
C2Cl6 hexachloroethane 4 A1u 61 87 26 0.698
C2Cl6 hexachloroethane 12 Eu 114 164 50 0.696
C6H6 Benzene 8 B2g 703 477 -226 1.473
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 315 101 0.679
C2H4+ Ethylene cation 4 Au 84 -65 -150 -1.285
C2H2 Acetylene 4 Πg 612 357 -255 1.713
HCN+ hydrogen cyanide cation 1 Σ 3050 3743 693 0.815
HCN+ hydrogen cyanide cation 2 Σ 1800 2790 990 0.645
CH3CCH propyne 9 E 633 486 -147 1.303
CH3CCH propyne 10 E 328 217 -111 1.511
CHONH2 formamide 12 A" 289 -129 -418 -2.237
C3F8 perfluoropropane 13 A2 276 211 -65 1.309
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 57 -18 1.319
CH3COCH2CH3 2-Butanone 33 A" 87 35 -52 2.494
CH3COOCH3 methyl acetate 27 A" 110 68 -42 1.624
C10H8 naphthalene 12 Au 581 442 -139 1.314
C10H8 naphthalene 27 B2g 770 412 -358 1.869
C10H8 naphthalene 28 B2g 461 -161 -622 -2.862
C9H8 Indene 40 A" 690 503 -187 1.371
C9H8 Indene 41 A" 549 430 -118 1.275
C6H5NO2 Nitrobenzene 22 B1 675 470 -205 1.435
C6H5CHCH2 Styrene 38 A" 633 434 -199 1.458
C6H5CN phenyl cyanide 19 B1 688 519 -169 1.325
C6H5CHO benzaldehyde 32 A" 688 478 -210 1.440
C6H4O2 parabenzoquinone 17 B2g 241 170 -71 1.421
C6H4O2 parabenzoquinone 30 B3u 109 85 -23 1.276
CHCCH2CH3 1-Butyne 22 A" 630 493 -137 1.277
C3H6O 2-Propen-1-ol 24 A 188 108 -80 1.747
C6H5Cl chlorobenzene 18 B1 685 462 -222 1.480
C5H8 Cyclopentene 18 A' 254 173 -81 1.470
CH2NN diazomethane 6 B1 406 -104 -510 -3.911
C6F6 hexafluorobenzene 7 B2g 719 195 -524 3.681
C6F6 hexafluorobenzene 8 B2g 205 -222 -427 -0.924
NH2CN cyanamide 5 A' 408 655 247 0.623
C4H6O2 2,3-Butanedione 21 Bg 240 119 -121 2.009
C4H2 Diacetylene 7 Πg 482 227 -255 2.124
C4H2 Diacetylene 8 Πu 630 425 -205 1.481
F2CCCF2 tetrafluoroallene 11 E 90 66 -24 1.361
C6H5F Fluorobenzene 18 B1 685 491 -194 1.394
C2H3NO3 Oxamic acid 3 A' 2600 3423 823 0.760
C2H3NO3 Oxamic acid 16 A" 984 759 -225 1.297
C2H3NO3 Oxamic acid 21 A" 162 52 -110 3.097
CH3CCCH3 2-Butyne 16 E" 371 158 -213 2.341
C3H6O Oxetane 18 B1 90 -86 -176 -1.040
C3O2 Carbon suboxide 7 Πu 61 100 39 0.609
HCNO fulminic acid 5 Π 224 -360 -584 -0.622
C6H4F2 1,4-difluorobenzene 16 B2g 692 478 -214 1.446
C5H8 1,4-Pentadiene 16 A 137 290 153 0.472
C5H8 1,4-Pentadiene 33 B 331 93 -238 3.546
HCCCl Chloroacetylene 5 Π 326 147 -179 2.215
C6H8 1,4-Cyclohexadiene 19 B1u 108 79 -29 1.375
CO+ carbon monoxide cation 1 Σ 2214 2722 508 0.813
C6H6 Benzvalene 10 A1 996 740 -256 1.345
C2F2 difluoroacetylene 4 Πg 270 174 -96 1.555
C6H10 2-Hexyne 24 A' 272 185 -87 1.469
C6H10 2-Hexyne 25 A' 115 84 -31 1.364
C6H10 2-Hexyne 38 A" 392 239 -153 1.638
H2CS- thioformaldehyde anion 4 B1 450 -194 -644 -2.323
NaOH sodium hydroxide 3 Π 300 120 -180 2.491
FCO+ Carbonyl fluoride cation 3 Π 650 508 -142 1.279
CN Cyano radical 1 Σ 2069 2699 631 0.766
C2H Ethynyl radical 2 Σ 1841 2343 502 0.786
C2H Ethynyl radical 3 Π 372 771 400 0.482
C2H+ Ethynyl cation 3 Π 550 786 237 0.699
CH3OO methylperoxy radical 12 A" 170 129 -41 1.320
CH3 Methyl radical 2 A2" 606 376 -231 1.615
CH2OH Hydroxymethyl radical 8 A 482 742 260 0.650
CH2OH Hydroxymethyl radical 9 A 234 435 201 0.538
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 864 -272 1.315
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 123 -141 2.144
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 89 -269 4.017
C6H6 2,4-Hexadiyne 14 E' 353 143 -210 2.477
CHCl2 dichloromethyl radical 4 A' 190 302 112 0.629
CH2CHO Vinyloxy radical 10 A" 703 1016 313 0.692
C4H6 Methylenecyclopropane 17 B1 360 264 -96 1.365
C2Cl2 dichloroacetylene 4 Πg 333 -58 -391 -5.753
C2Cl2+ dichloroacetylene cation 5 Πu 233 168 -65 1.387
BF3+ boron trifluoride cation 2 A2" 202 518 316 0.390
BF3+ boron trifluoride cation 3 E' 1662 2153 492 0.772
O2+ diatomic oxygen cation 1 Σg 1906 1266 -640 1.506
O2 Oxygen diatomic 1 Σg 1484 1140 -344 1.302
O2 Oxygen diatomic 1 Σg 794 1140 345 0.697
O3 Ozone 3 B2 1042 2244 1202 0.464
NO Nitric oxide 1 Σ 1904 3690 1786 0.516
NO2 Nitrogen dioxide 3 B2 1618 2141 523 0.756
N2O4 Dinitrogen tetroxide 9 B2u 265 181 -84 1.461
N2O3 Dinitrogen trioxide 9 A" 63 165 102 0.382
C3O Tricarbon monoxide 5 Π 109 167 58 0.654
VO Vanadium monoxide 1 Σ 1011 2092 1081 0.483
Li2O dilithium oxide 3 Πu 112 62 -50 1.811
FO Oxygen monofluoride 1 Σ 1053 1456 403 0.723
C3 carbon trimer 3 Πu 63 166 102 0.383
SiP Silicon monophosphide 1 Σ 616 1260 644 0.489
Cu2 Copper dimer 1 Σg 265 383 118 0.691
ZnH2 Zinc hydride 3 Πu 633 494 -139 1.281
PO Phosphorus monoxide 1 Σ 1233 3869 2635 0.319
AlO Aluminum monoxide 1 Σ 979 724 -255 1.352
SCN thiocyanato radical 1 Σ 1942 2414 472 0.804
ClOO chloroperoxy radical 2 A' 414 1030 616 0.402
ClOO chloroperoxy radical 3 A' 201 468 267 0.430
OPCl Phosphorus oxychloride 2 A' 308 478 170 0.644
OPCl Phosphorus oxychloride 3 A' 492 286 -206 1.721
NCO isocyanato radical 1 Σ 1921 2366 445 0.812
H2POH Phosphinous acid 9 A" 375 258 -117 1.455
AsN Arsenic mononitride 1 Σ 1069 823 -245 1.298
Mg2 Magnesium diatomic 1 Σg 51 21 -30 2.423
ZnCH3 Zinc monomethyl 6 E 315 605 290 0.520
ZnCN Zinc monocyanide 3 Π 212 -37 -249 -5.769
ONONO Nitrosyl nitrite 9 B2 380 263 -117 1.442