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 CCD/6-31G*
Calculated values were scaled by 0.9465.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 168 55 0.674
CH3OH Methyl alcohol 12 A" 200 330 130 0.606
C2Cl6 hexachloroethane 12 Eu 114 165 51 0.692
C6H6 Benzene 8 B2g 703 541 -162 1.300
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 309 95 0.693
C2H4+ Ethylene cation 4 Au 84 138 54 0.609
C2H2 Acetylene 4 Πg 612 420 -192 1.458
HCN+ hydrogen cyanide cation 1 Σ 3050 3500 450 0.871
HCN+ hydrogen cyanide cation 2 Σ 1800 2712 912 0.664
CHONH2 formamide 12 A" 289 -184 -473 -1.570
C3F8 perfluoropropane 13 A2 276 215 -61 1.285
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 57 -18 1.323
CH3COCH2CH3 2-Butanone 33 A" 87 42 -45 2.086
CH3COOCH3 methyl acetate 27 A" 110 80 -30 1.374
C10H8 naphthalene 27 B2g 770 428 -342 1.799
C10H8 naphthalene 28 B2g 461 362 -99 1.273
C6H4O2 parabenzoquinone 17 B2g 241 188 -53 1.279
C6H4O2 parabenzoquinone 30 B3u 109 85 -24 1.284
C3H6O 2-Propen-1-ol 24 A 188 105 -83 1.788
C6H5Cl chlorobenzene 18 B1 685 533 -152 1.284
C5H12 Pentane 23 A2 131 103 -28 1.274
C4H8S Thiophene, tetrahydro- 5 A 1464 2942 1478 0.498
C4H8S Thiophene, tetrahydro- 6 A 1441 2942 1501 0.490
C4H8S Thiophene, tetrahydro- 7 A 1321 2920 1599 0.452
C4H8S Thiophene, tetrahydro- 8 A 1276 2920 1644 0.437
C4H8S Thiophene, tetrahydro- 11 A 1023 1460 437 0.701
C4H8S Thiophene, tetrahydro- 12 A 888 1457 569 0.609
C4H8S Thiophene, tetrahydro- 13 A 829 1336 507 0.620
C4H8S Thiophene, tetrahydro- 14 A 822 1314 492 0.626
C4H8S Thiophene, tetrahydro- 15 A 678 1293 615 0.524
C4H8S Thiophene, tetrahydro- 16 A 472 1264 792 0.373
C4H8S Thiophene, tetrahydro- 17 A 290 1216 926 0.239
C5H8 Cyclopentene 18 A' 254 158 -96 1.612
NH2CN cyanamide 5 A' 408 663 255 0.615
C4H6O2 2,3-Butanedione 21 Bg 240 124 -116 1.933
C4H2 Diacetylene 7 Πg 482 357 -125 1.351
C4H2 Diacetylene 8 Πu 630 496 -134 1.269
C6H5F Fluorobenzene 18 B1 685 539 -146 1.270
C2H3NO3 Oxamic acid 3 A' 2600 3451 851 0.753
C2H3NO3 Oxamic acid 16 A" 984 775 -209 1.269
C2H3NO3 Oxamic acid 20 A" 315 231 -84 1.366
C2H3NO3 Oxamic acid 21 A" 162 38 -124 4.319
CH3CCCH3 2-Butyne 16 E" 371 228 -143 1.628
C3H6O Oxetane 18 B1 90 -41 -131 -2.172
C6H4F2 1,4-difluorobenzene 16 B2g 692 536 -156 1.292
C5H8 1,4-Pentadiene 16 A 137 287 150 0.477
HCCCl Chloroacetylene 5 Π 326 229 -97 1.421
CH3SSCH3 Disulfide, dimethyl 13 A 117 92 -25 1.269
C6H6 Benzvalene 10 A1 996 750 -246 1.329
H2CS- thioformaldehyde anion 4 B1 450 -109 -559 -4.114
NaOH sodium hydroxide 3 Π 300 161 -139 1.862
CN Cyano radical 1 Σ 2069 2521 452 0.821
C2H Ethynyl radical 2 Σ 1841 2253 412 0.817
C2H Ethynyl radical 3 Π 372 732 361 0.507
CH3 Methyl radical 2 A2" 606 410 -197 1.480
CH2OH Hydroxymethyl radical 8 A 482 705 223 0.683
CH2OH Hydroxymethyl radical 9 A 234 416 182 0.563
HCCN cyanomethylene 5 Π 129 -469 -597 -0.275
CHCl2 dichloromethyl radical 4 A' 190 299 109 0.636
C4H6 Methylenecyclopropane 17 B1 360 272 -88 1.325
C2Cl2 dichloroacetylene 4 Πg 333 197 -136 1.688
N2 Nitrogen diatomic 1 Σg 2359 1634 -724 1.443
FOOF Perfluoroperoxide 1 A 1210 946 -264 1.280
O3 Ozone 3 B2 1042 1674 632 0.623
NO Nitric oxide 1 Σ 1904 3120 1215 0.610
NO2 Nitrogen dioxide 3 B2 1618 3757 2139 0.431
N2O3 Dinitrogen trioxide 9 A" 63 136 73 0.463
VO Vanadium monoxide 1 Σ 1011 1863 851 0.543
Li2O dilithium oxide 3 Πu 112 81 -31 1.381
C3 carbon trimer 3 Πu 63 101 38 0.628
ZnH2 Zinc hydride 3 Πu 633 486 -147 1.302
PO Phosphorus monoxide 1 Σ 1233 3054 1821 0.404
AlO Aluminum monoxide 1 Σ 979 763 -217 1.284
FO2 Dioxygen monofluoride 1 A' 1487 2454 967 0.606
FO2 Dioxygen monofluoride 2 A' 579 1146 566 0.506
FO2 Dioxygen monofluoride 3 A' 376 617 241 0.609
ClOO chloroperoxy radical 2 A' 414 1010 596 0.410
ClOO chloroperoxy radical 3 A' 201 466 265 0.432
PN+ phosphorus nitride cation 1 Σ 1200 2126 926 0.564
Cl3- trichloride anion 2 Σu 327 214 -113 1.525
CaS Calcium sulfide 1 Σ 462 351 -112 1.318
OPCl Phosphorus oxychloride 2 A' 308 493 185 0.624
OPCl Phosphorus oxychloride 3 A' 492 301 -191 1.634
H2POH Phosphinous acid 9 A" 375 252 -124 1.491
Mg2 Magnesium diatomic 1 Σg 51 310 259 0.165
ZnCH3 Zinc monomethyl 6 E 315 603 288 0.522
ClONO chlorine nitrite 4 A' 406 595 189 0.682
ZnCN Zinc monocyanide 3 Π 212 75 -137 2.844
ONONO Nitrosyl nitrite 9 B2 380 569 189 0.667