return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Calculated > Vibrations > Bad Calculations > Bad vib. Calc. vs exp. OR Resources > Bad Calculations > Vibrations > Bad vib. Calc. vs exp.

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 PBEPBE/6-31G*
Calculated values were scaled by 0.9857.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 178 65 0.635
CH3CONH2 Acetamide 20 A 259 155 -104 1.675
CH3COOH Acetic acid 18 A" 93 61 -32 1.528
CH3OH Methyl alcohol 12 A" 200 343 143 0.583
CH3COCH3 Acetone 12 A2 77 32 -45 2.430
C2H6O2S Dimethyl sulfone 13 A2 326 260 -66 1.252
C2H6O2S Dimethyl sulfone 20 B1 262 207 -55 1.264
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 306 92 0.699
C2H4+ Ethylene cation 4 Au 84 -581 -666 -0.145
C2H2 Acetylene 4 Πg 612 445 -167 1.375
CHONH2 formamide 12 A" 289 72 -216 3.989
CH3COCl Acetyl Chloride 15 A" 166 127 -39 1.306
CBr2F2 Methane, dibromodifluoro- 3 A1 140 313 173 0.448
C2F6 hexafluoroethane 4 A1u 68 43 -25 1.587
C3F8 perfluoropropane 13 A2 276 205 -71 1.347
CF2CCl2 difluorodichloroethylene 7 B1 1327 541 -786 2.454
CF2CCl2 difluorodichloroethylene 8 B1 989 309 -680 3.198
CF2CCl2 difluorodichloroethylene 11 B2 564 436 -128 1.293
CF2CCl2 difluorodichloroethylene 12 B2 323 177 -146 1.820
C3H6O 2-Propen-1-ol 24 A 188 114 -74 1.646
C2F4 Tetrafluoroethylene 7 B2g 508 414 -94 1.228
C5H8 Cyclopentene 18 A' 254 140 -114 1.818
C2H3N3 1H-1,2,4-Triazole 18 A" 640 522 -118 1.227
C4H4N2 Pyridazine 13 A2 421 341 -80 1.234
C2H2N4 sym-tetrazine 5 Au 335 271 -64 1.237
C2H2N4 sym-tetrazine 18 B3u 254 113 -141 2.253
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 330 -879 3.667
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 398 -135 1.340
C6F6 hexafluorobenzene 7 B2g 715 466 -249 1.535
C6F6 hexafluorobenzene 8 B2g 243 174 -69 1.394
C6F6 hexafluorobenzene 20 E2u 175 129 -46 1.359
NH2CN cyanamide 5 A' 408 589 181 0.692
C4H6O2 2,3-Butanedione 9 Ag 614 497 -117 1.235
C4H6O2 2,3-Butanedione 13 Au 1111 911 -200 1.220
C4H6O2 2,3-Butanedione 21 Bg 240 98 -142 2.438
C4H2 Diacetylene 8 Πu 630 504 -126 1.250
C5H12 Propane, 2,2-dimethyl- 12 T1 203 311 108 0.652
C2H3NO3 Oxamic acid 3 A' 2600 3455 855 0.752
C2H3NO3 Oxamic acid 15 A' 328 254 -74 1.289
C2H3NO3 Oxamic acid 16 A" 984 775 -209 1.269
C2H3NO3 Oxamic acid 21 A" 162 68 -94 2.372
C3H6O Oxetane 18 B1 90 -6 -95 -15.851
C3O2 Carbon suboxide 7 Πu 61 123 62 0.495
HCNO fulminic acid 5 Π 224 -231 -455 -0.969
C5H8 1,4-Pentadiene 16 A 137 287 150 0.477
HCCCl Chloroacetylene 5 Π 326 255 -71 1.279
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 185 -42 1.228
CH3ONO Methyl nitrite 15 A" 186 142 -44 1.312
GeO2 Germanium dioxide 3 Πu 196 160 -36 1.223
LiOH lithium hydroxide 3 Π 257 211 -46 1.219
SiF2+ Silicon difluoride cation 2 A1 350 272 -78 1.288
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 210 66 0.687
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 340 -116 1.340
FCO+ Carbonyl fluoride cation 3 Π 650 522 -128 1.244
CH3OO methylperoxy radical 12 A" 170 137 -33 1.243
CH3 Methyl radical 2 A2" 606 459 -147 1.320
CH2OH Hydroxymethyl radical 9 A 234 446 212 0.525
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 872 -264 1.303
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 158 -106 1.669
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 105 -253 3.421
CHCl2 dichloromethyl radical 4 A' 190 297 107 0.640
C4H6 Methylenecyclopropane 17 B1 360 273 -87 1.320
C2Cl2 dichloroacetylene 4 Πg 333 202 -131 1.652
HClO4 perchloric acid 12 A" 191 149 -42 1.279
ClFO3 Perchloryl fluoride 6 E 405 320 -85 1.267
SOCl2 thionyl chloride 4 A' 194 158 -36 1.229
MgF2 Magnesium fluoride 3 Πu 165 133 -32 1.242
F2SO Thionyl Fluoride 4 A' 378 306 -72 1.234
SF4 Sulfur tetrafluoride 4 A1 228 171 -57 1.336
BrF3 Bromine trifluoride 3 A1 242 196 -46 1.235
HSO3F Fluorosulfonic acid 11 A 390 317 -73 1.232
BrF5 bromine pentafluoride 6 B2 281 188 -93 1.492
BrF5 bromine pentafluoride 8 E 415 340 -75 1.220
ClF3 Chlorine trifluoride 3 A1 328 259 -69 1.268
ClF3 Chlorine trifluoride 6 B2 442 356 -86 1.243
Cl2O Dichlorine monoxide 3 B2 686 551 -135 1.245
NCl3 nitrogen trichloride 3 E 642 513 -129 1.252
PCl5 Phosphorus pentachloride 2 A1' 370 259 -111 1.427
PCl5 Phosphorus pentachloride 7 E' 100 82 -18 1.226
N2O4 Dinitrogen tetroxide 9 B2u 265 189 -76 1.404
N2O3 Dinitrogen trioxide 9 A" 63 140 77 0.449
SF5 Sulfur pentafluoride 3 A1 554 440 -114 1.258
SF5 Sulfur pentafluoride 8 E 525 430 -95 1.220
SF5 Sulfur pentafluoride 9 E 387 296 -91 1.309
C3 carbon trimer 3 Πu 63 110 46 0.579
CaOH Calcium monohydroxide 2 Σ 353 601 248 0.587
CaOH Calcium monohydroxide 3 Π 609 294 -315 2.072
C4 Carbon tetramer 4 Πg 323 209 -114 1.548
Cu2 Copper dimer 1 Σg 265 410 146 0.645
SiH- silicon monohydride anion 1 Σ 2175 1730 -445 1.257
SF5Cl sulfur chloropentafluoride 5 B1 625 431 -194 1.451
SF5Cl sulfur chloropentafluoride 7 B2 505 287 -218 1.760
SF5Cl sulfur chloropentafluoride 11 E 397 225 -172 1.762
ZnH2 Zinc hydride 3 Πu 633 482 -150 1.312
C2H4O4 Formic acid dimer 13 Au 1050 74 -976 14.222
ClONO2 Chlorine nitrate 7 A' 273 222 -52 1.233
B2H6 Diborane 14 B2u 368 298 -70 1.234
H2OH2O water dimer 6 A' 311 495 184 0.628
H2OH2O water dimer 7 A' 143 251 108 0.570
H2OH2O water dimer 11 A" 108 189 81 0.571
H2OH2O water dimer 12 A" 88 -133 -221 -0.660
H2POH Phosphinous acid 9 A" 375 226 -149 1.659
Mg2 Magnesium diatomic 1 Σg 51 103 52 0.498
ClOF3 Chlorine trifluoride oxide 6 A' 224 171 -53 1.307
ZnCH3 Zinc monomethyl 6 E 315 599 284 0.526
ClONO chlorine nitrite 4 A' 406 299 -107 1.360
ClONO chlorine nitrite 5 A' 270 158 -112 1.712
CH3BO Borane, methyloxo- 7 E 897 1422 525 0.631