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 MP2/CEP-31G*
Calculated values were scaled by 0.9494.

Species Name mode int rot Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 164 51 0.689
C4H10O Ethoxy ethane 12 A1 240 184 -56 1.306
C4H10O Ethoxy ethane 20 A2 137 88 -49 1.556
CH3COOH Acetic acid 18 torsion A" 93 70 -23 1.320
CH3OH Methyl alcohol 12 torsion A" 200 325 125 0.616
C2H6O2S Dimethyl sulfone 20 B1 262 199 -63 1.314
CH3CCl3 Ethane, 1,1,1-trichloro- 6 torsion A2 214 307 93 0.697
C2H4 Ethylene 7 B2g 940 730 -210 1.288
C2H4+ Ethylene cation 4 torsion Au 84 208 124 0.405
HCN+ hydrogen cyanide cation 1 Σ 3050 3903 853 0.781
HCN+ hydrogen cyanide cation 2 Σ 1800 2827 1027 0.637
CHONH2 formamide 12 torsion A" 289 -224 -512 -1.291
CH3SCH3+ dimethyl sulfide cation 15 B1 172 129 -43 1.328
C3F8 perfluoropropane 13 A2 276 214 -62 1.292
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 59 -16 1.278
CH3COOCH3 methyl acetate 27 torsion A" 110 50 -60 2.188
C6H4Cl2 1,2-dichlorobenzene 14 A2 695 546 -149 1.273
CH3CH2CH2CH3 Butane 5 Ag 1442 405 -1037 3.561
CH3CH2CH2CH3 Butane 8 Ag 1151 821 -330 1.402
CH3CH2CH2CH3 Butane 30 Bu 1461 2931 1470 0.498
CH3CH2CH2CH3 Butane 34 Bu 1009 3015 2006 0.335
C3H6O 2-Propen-1-ol 24 A 188 102 -86 1.846
CH2ClCHO chloroacetaldehyde 15 torsion A 27 48 21 0.566
CH2ClCHO chloroacetaldehyde 15 A" 59 151 92 0.391
C3H2N2 Malononitrile 6 A1 167 130 -37 1.288
CHSNH2 thioformamide 12 A" 393 201 -192 1.952
C3F6 hexafluoropropene 21 A" 60 35 -25 1.727
C5H8 Cyclopentene 18 torsion A' 254 187 -67 1.355
C5H8 Spiropentane 8 A2 919 721 -198 1.275
C6F6 hexafluorobenzene 7 B2g 719 540 -179 1.331
NH2CN cyanamide 5 torsion A' 408 711 303 0.574
C4H6O2 2,3-Butanedione 21 torsion Bg 240 119 -121 2.021
CH(CN)3 tricyanomethane 12 E 149 116 -33 1.283
CH2FCH2CH3 1-Fluoropropane 13 A' 1391 998 -393 1.393
F2CCCF2 tetrafluoroallene 11 E 90 53 -37 1.688
CH2CO Ketene 6 B1 528 316 -212 1.670
C2H3NO3 Oxamic acid 3 A' 2600 3435 835 0.757
C2H3NO3 Oxamic acid 15 A' 328 251 -77 1.307
C2H3NO3 Oxamic acid 16 A" 984 772 -212 1.274
C2H3NO3 Oxamic acid 20 A" 315 194 -121 1.621
C2H3NO3 Oxamic acid 21 A" 162 25 -137 6.363
CH3CCCH3 2-Butyne 16 E" 371 173 -198 2.144
C3H6O Oxetane 18 B1 90 -34 -124 -2.642
C3O2 Carbon suboxide 7 Πu 61 182 121 0.334
HCNO fulminic acid 5 torsion Π 224 -343 -567 -0.653
C5H8 1,4-Pentadiene 16 A 137 283 146 0.484
C5H8 1,4-Pentadiene 17 torsion A 102 78 -24 1.301
C5H8 1,4-Pentadiene 17 torsion A 102 78 -24 1.301
P(CH3)3 trimethylphosphine 22 E 259 193 -66 1.339
CH3SSCH3 Disulfide, dimethyl 13 torsion A 117 92 -25 1.270
CO+ carbon monoxide cation 1 Σ 2184 2766 582 0.790
C6H6 Benzvalene 10 A1 996 718 -278 1.387
H2CS- thioformaldehyde anion 4 B1 450 -169 -619 -2.657
CH2CHSH Ethenethiol 13 A" 972 758 -214 1.282
CH2ClCCCl 1,3-dichloropropyne 14 A" 337 262 -75 1.286
LiOH lithium hydroxide 3 Π 257 381 124 0.674
SiF2+ Silicon difluoride cation 2 A1 350 276 -74 1.268
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 213 69 0.675
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 329 -127 1.386
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 128 -43 1.332
CH2NH+ Methanimine cation 4 A' 1370 1799 429 0.762
CN Cyano radical 1 Σ 2042 2634 592 0.775
C2H Ethynyl radical 3 torsion Π 372 789 417 0.471
C2H+ Ethynyl cation 3 Π 550 804 254 0.684
CH3 Methyl radical 2 torsion A2" 606 403 -204 1.506
CH2OH Hydroxymethyl radical 8 torsion A 482 756 274 0.638
CH2OH Hydroxymethyl radical 9 torsion A 234 435 201 0.538
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 853 -283 1.331
C6H8 (Z)-hexa-1,3,5-triene 19 torsion A2 264 148 -116 1.785
C6H8 (Z)-hexa-1,3,5-triene 24 torsion B1 358 105 -253 3.409
HCCN cyanomethylene 5 Π 129 -546 -674 -0.236
CCl3 Trichloromethyl radical 2 A1 251 362 111 0.693
CHCl2 dichloromethyl radical 4 A' 190 292 102 0.651
CH2CHO Vinyloxy radical 12 torsion A" 404 317 -87 1.276
C4H6 Methylenecyclopropane 17 B1 360 270 -90 1.332
CH2Cl chloromethyl radical 4 B1 402 -323 -725 -1.244
HNC+ hydrogen isocyanide cation 2 Σ 2195 2630 435 0.835
HNC+ hydrogen isocyanide cation 3 Π 578 844 267 0.684
BF3+ boron trifluoride cation 5 B2 1791 3271 1480 0.548
O2+ diatomic oxygen cation 1 Σg 1873 1226 -647 1.528
HN3+ Hydrazoic acid cation 2 A' 1850 3203 1353 0.578
HN3+ Hydrazoic acid cation 4 A' 850 652 -198 1.303
HOCl+ hypochlorous acid cation 3 A' 830 1326 495 0.626
HeH+ Helium hydride cation 1 Σ 2911 4984 2073 0.584
O3 Ozone 3 B2 1042 2343 1300 0.445
NO Nitric oxide 1 Σ 1876 4210 2334 0.446
NO2 Nitrogen dioxide 3 B2 1618 2035 417 0.795
BCl3+ Boron Trichloride cation 3 E' 1104 1514 410 0.729
N2O4 Dinitrogen tetroxide 9 B2u 265 179 -86 1.484
N2O3 Dinitrogen trioxide 9 torsion A" 63 154 91 0.410
C3O Tricarbon monoxide 5 Π 109 245 136 0.444
NaO2 Sodium superoxide 3 B2 333 510422 510089 0.001
FO Oxygen monofluoride 1 Σ 1033 2262 1229 0.457
SiC2 Silicon dicarbide 3 B2 196 -237 -433 -0.829
C3 carbon trimer 3 Πu 63 295 232 0.215
LiO2 Lithium dioxide 3 B2 509 3136 2627 0.162
MgOH magnesium hydroxide 3 torsion Π 188 116 -72 1.616
C4 Carbon tetramer 4 Πg 323 555 232 0.582
SiH2D2 silane-d2 6 B1 2183 1554 -629 1.405
SiH2D2 silane-d2 8 B2 1601 2150 549 0.745
PO Phosphorus monoxide 1 Σ 1220 5350 4130 0.228
AlO Aluminum monoxide 1 Σ 965 634 -331 1.522
SCN thiocyanato radical 1 Σ 1942 2441 498 0.796
ClOO chloroperoxy radical 2 A' 414 1025 611 0.404
ClOO chloroperoxy radical 3 A' 201 462 261 0.436
B4H10 Tetraborane(10) 11 A1 785 569 -216 1.380
B4H10 Tetraborane(10) 12 A1 559 238 -321 2.349
B4H10 Tetraborane(10) 19 A2 662 413 -249 1.601
B4H10 Tetraborane(10) 36 B2 236 373 137 0.633
FSN Thiazyl fluoride 3 A' 366 289 -77 1.264
BH3PH3 borane phosphine 12 E 447 352 -95 1.270
B5H9 pentaborane9 13 B1 240 607 367 0.396
B5H9 pentaborane9 16 B2 1036 751 -285 1.380
B5H9 pentaborane9 18 B2 600 463 -137 1.297
B5H9 pentaborane9 22 E 1409 1049 -360 1.343
OPCl Phosphorus oxychloride 2 A' 308 480 172 0.642
OPCl Phosphorus oxychloride 3 A' 492 283 -209 1.739
NCO isocyanato radical 1 Σ 1921 2412 490 0.797
H2OH2O water dimer 8 A' 103 165 62 0.626
H2OH2O water dimer 11 A" 108 161 53 0.671
H2OH2O water dimer 12 A" 88 139 51 0.635
H2POH Phosphinous acid 9 A" 375 258 -118 1.456
Mg2 Magnesium diatomic 1 Σg 48 26 -22 1.852
ClOF3 Chlorine trifluoride oxide 5 A' 319 249 -70 1.279
ClOF3 Chlorine trifluoride oxide 9 A" 412 323 -89 1.276
CHFCl Chlorofluoromethyl radical 6 A 540 385 -155 1.404
H2CNCN cyanamide, methylene 3 A' 2208 2989 781 0.739
H2CNCN cyanamide, methylene 4 A' 1621 2041 420 0.794
SNO Nitrogen oxide sulfide 3 A' 792 510 -283 1.555
ONNO NO dimer 3 A1 135 286 152 0.470
ONNO NO dimer 4 torsion A2 117 264 147 0.443
AlNC Aluminum isocyanide 3 Π 100 44 -56 2.251
ONONO Nitrosyl nitrite 9 B2 380 293 -87 1.297