return to home page Computational Chemistry Comparison and Benchmark DataBase Release 22 (May 2022) Standard Reference Database 101 National Institute of Standards and Technology
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Bad vibrational frequency predictions

19 02 11 15 45

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 HF/CEP-121G*
Calculated values were scaled by 0.9034.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 166 53 0.680
C4H10O Ethoxy ethane 20 A2 137 87 -50 1.567
CH3OH Methyl alcohol 12 torsion A" 200 311 111 0.643
C2H4+ Ethylene cation 4 torsion Au 84 373 289 0.226
CHONH2 formamide 12 torsion A" 289 -165 -454 -1.745
CH3COOCH3 methyl acetate 27 torsion A" 110 70 -40 1.572
C6H4O2 parabenzoquinone 17 B2g 241 181 -60 1.334
C3H6O 2-Propen-1-ol 24 A 188 108 -80 1.747
CH2ClCHO chloroacetaldehyde 15 torsion A 27 50 23 0.539
CH2ClCHO chloroacetaldehyde 15 A" 59 141 82 0.420
C3F6 hexafluoropropene 21 A" 60 39 -21 1.521
C5H8 Cyclopentene 18 torsion A' 254 144 -110 1.769
NH2CN cyanamide 5 torsion A' 408 691 283 0.590
C4H6O2 2,3-Butanedione 21 torsion Bg 240 115 -125 2.089
C4H2 Diacetylene 6 Πg 627 1228 601 0.510
C4H2 Diacetylene 7 Πg 482 708 226 0.681
C4H2 Diacetylene 8 Πu 630 925 295 0.681
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 991 -400 1.404
C6H4 Benzyne 24 B2 472 244 -228 1.932
C2H3NO3 Oxamic acid 3 A' 2600 3456 856 0.752
C2H3NO3 Oxamic acid 20 A" 315 227 -88 1.388
C2H3NO3 Oxamic acid 21 A" 162 18 -144 9.168
C3O2 Carbon suboxide 7 Πu 61 148 87 0.411
HCNO fulminic acid 5 torsion Π 224 543 319 0.412
C5H8 1,4-Pentadiene 16 A 137 286 149 0.479
P(CH3)3 trimethylphosphine 22 E 259 194 -65 1.334
C2F2 difluoroacetylene 4 Πg 270 415 145 0.651
H2CS- thioformaldehyde anion 4 B1 450 -248 -698 -1.815
C4H6O Cyclobutanone 13 A2 909 626 -283 1.452
C4H6O Cyclobutanone 20 B1 63 8 -55 8.157
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 210 66 0.685
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 119 -52 1.432
C2H+ Ethynyl cation 3 Π 550 861 311 0.638
CH3 Methyl radical 2 torsion A2" 606 265 -342 2.291
CH2OH Hydroxymethyl radical 8 torsion A 482 787 305 0.612
CH2OH Hydroxymethyl radical 9 torsion A 234 377 143 0.621
ClCO carbonyl monochloride 3 A' 335 135 -199 2.472
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 844 -292 1.345
C6H8 (Z)-hexa-1,3,5-triene 19 torsion A2 264 128 -136 2.060
C6H8 (Z)-hexa-1,3,5-triene 24 torsion B1 358 90 -268 3.993
HCCN cyanomethylene 5 Π 129 -396 -525 -0.326
HNCS Isothiocyanic acid 5 A' 469 232 -237 2.018
CHCl2 dichloromethyl radical 4 A' 190 285 95 0.667
CH2Cl chloromethyl radical 4 B1 402 -406 -808 -0.990
HCP+ Phosphaethyne cation 2 Σ 1282 949 -333 1.351
FOOF Perfluoroperoxide 2 A 630 1047 417 0.602
FOOF Perfluoroperoxide 5 B 614 1033 419 0.594
N2O4 Dinitrogen tetroxide 3 Ag 265 412 147 0.643
N2O4 Dinitrogen tetroxide 4 torsion Au 82 47 -35 1.741
N2O3 Dinitrogen trioxide 6 A' 241 405 164 0.595
N2O3 Dinitrogen trioxide 7 A' 205 328 123 0.626
N2O3 Dinitrogen trioxide 8 A" 414 607 193 0.682
C3O Tricarbon monoxide 5 Π 109 226 117 0.482
NS Mononitrogen monosulfide 1 Σ 1204 795 -409 1.514
SiN Silicon nitride 1 Σ 1138 780 -359 1.460
SiC2 Silicon dicarbide 3 B2 196 -309 -505 -0.636
C3 carbon trimer 3 Πu 63 274 211 0.231
SiP Silicon monophosphide 1 Σ 611 410 -202 1.492
CP Carbon monophosphide 1 Σ 1226 879 -347 1.395
BH3CO Borane carbonyl 4 A1 691 454 -237 1.524
SiH2D2 silane-d2 6 B1 2183 1520 -663 1.436
SiH2D2 silane-d2 8 B2 1601 2103 502 0.761
AlO Aluminum monoxide 1 Σ 965 693 -272 1.392
C2H4O4 Formic acid dimer 17 Bu 3084 3491 407 0.883
C2H4O4 Formic acid dimer 24 Bu 268 191 -77 1.400
ClOO chloroperoxy radical 1 A' 1443 1084 -359 1.331
ClOO chloroperoxy radical 2 A' 414 628 214 0.659
ClOO chloroperoxy radical 3 A' 201 395 193 0.510
B4H10 Tetraborane(10) 11 A1 785 474 -311 1.657
B4H10 Tetraborane(10) 12 A1 559 210 -349 2.656
B4H10 Tetraborane(10) 19 A2 662 385 -277 1.720
B4H10 Tetraborane(10) 36 B2 236 161 -75 1.466
Cl3- trichloride anion 2 Σu 327 -94 -421 -3.468
BH3PH3 borane phosphine 5 A1 572 362 -210 1.578
B5H9 pentaborane9 13 B1 240 588 348 0.408
B5H9 pentaborane9 16 B2 1036 772 -264 1.343
B5H9 pentaborane9 18 B2 600 428 -172 1.403
OPCl Phosphorus oxychloride 2 A' 308 478 170 0.644
OPCl Phosphorus oxychloride 3 A' 492 305 -187 1.613
F3- trifluoride anion 2 Σu 550 -434 -984 -1.268
H2POH Phosphinous acid 9 A" 375 252 -123 1.487
H2NN Isodiazene 5 B2 2805 3284 479 0.854
Mg2 Magnesium diatomic 1 Σg 48 2 -45 19.422
CHFCl Chlorofluoromethyl radical 6 A 540 387 -153 1.396
H2CNCN cyanamide, methylene 3 A' 2208 2959 751 0.746
H2CNCN cyanamide, methylene 4 A' 1621 2292 671 0.707
C2H3NO Nitrosoethylene 11 A' 490 341 -149 1.437
H2COO Dioxymethyl radical 6 A' 908 513 -395 1.771
NNS Nitrogen sulfide 2 Σ 752 522 -230 1.440
SNO Nitrogen oxide sulfide 1 A' 1527 2232 705 0.684
SNO Nitrogen oxide sulfide 3 A' 792 473 -319 1.675
ONNO NO dimer 2 A1 239 560 320 0.428
ONNO NO dimer 3 A1 135 390 256 0.344
ONNO NO dimer 4 torsion A2 117 -123 -240 -0.948
ONNO NO dimer 6 B2 429 875 445 0.491
AlNC Aluminum isocyanide 3 Π 100 167 67 0.598
ClONO chlorine nitrite 4 A' 406 684 278 0.594
HSO3 Hydroxysulfonyl radical 4 A 1097 816 -282 1.345
ONONO Nitrosyl nitrite 9 B2 380 711 331 0.535
NSO sulfinyl amidogen 2 A' 1010 669 -341 1.510