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 PBEPBE/6-31+G**
Calculated values were scaled by 0.9886.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 179 66 0.632
CH3CONH2 Acetamide 20 A 259 198 -61 1.307
CH3COOH Acetic acid 18 A" 93 53 -40 1.769
CH3OH Methyl alcohol 12 A" 200 311 111 0.643
C2H6O2S Dimethyl sulfone 13 A2 326 267 -59 1.222
C2H6O2S Dimethyl sulfone 20 B1 262 208 -54 1.258
C2H4+ Ethylene cation 4 Au 84 -616 -700 -0.136
CH3COCl Acetyl Chloride 15 A" 166 117 -49 1.422
C2F6 hexafluoroethane 4 A1u 68 54 -14 1.257
C3F8 perfluoropropane 13 A2 276 210 -66 1.314
C3H6O 2-Propen-1-ol 24 A 188 111 -77 1.687
C3H2N2 Malononitrile 6 A1 167 137 -30 1.220
C4H8S Thiophene, tetrahydro- 5 A 1464 2963 1499 0.494
C4H8S Thiophene, tetrahydro- 6 A 1441 2963 1522 0.486
C4H8S Thiophene, tetrahydro- 7 A 1321 2947 1626 0.448
C4H8S Thiophene, tetrahydro- 8 A 1276 2947 1671 0.433
C4H8S Thiophene, tetrahydro- 12 A 888 1416 528 0.627
C4H8S Thiophene, tetrahydro- 13 A 829 1300 471 0.638
C4H8S Thiophene, tetrahydro- 14 A 822 1275 453 0.645
C4H8S Thiophene, tetrahydro- 15 A 678 1248 570 0.543
C4H8S Thiophene, tetrahydro- 16 A 472 1230 758 0.384
C4H8S Thiophene, tetrahydro- 17 A 290 1187 897 0.244
C5H8 Cyclopentene 18 A' 254 147 -107 1.731
C2H4O3 trioxolane124 21 B 193 159 -34 1.218
C4H4N2 Pyridazine 13 A2 421 340 -81 1.240
C2H2N4 sym-tetrazine 5 Au 335 273 -62 1.229
C2H2N4 sym-tetrazine 18 B3u 254 122 -132 2.078
C4H6O2 2,3-Butanedione 9 Ag 614 495 -119 1.241
C4H6O2 2,3-Butanedione 13 Au 1111 901 -210 1.234
C4H6O2 2,3-Butanedione 21 Bg 240 98 -142 2.454
C5H12 Propane, 2,2-dimethyl- 12 T1 203 313 110 0.649
C2H3NO3 Oxamic acid 3 A' 2600 3466 866 0.750
C2H3NO3 Oxamic acid 15 A' 328 255 -73 1.288
C2H3NO3 Oxamic acid 16 A" 984 783 -201 1.257
C2H3NO3 Oxamic acid 17 A" 815 656 -159 1.241
C2H3NO3 Oxamic acid 21 A" 162 66 -96 2.438
C3H6O Oxetane 12 A2 986 807 -179 1.222
C3H6O Oxetane 18 B1 90 -49 -139 -1.825
C3H6O Oxetane 23 B2 1228 999 -229 1.229
C3O2 Carbon suboxide 7 Πu 61 163 102 0.373
HCNO fulminic acid 5 Π 224 -148 -372 -1.512
C5H8 1,4-Pentadiene 16 A 137 289 152 0.474
HCCBr bromoacetylene 5 Π 295 450 155 0.655
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 187 -40 1.216
CH3ONO Methyl nitrite 15 A" 186 147 -39 1.268
C6H6 Benzvalene 10 A1 996 738 -258 1.350
C2F2 difluoroacetylene 4 Πg 270 214 -56 1.263
H2CS- thioformaldehyde anion 4 B1 450 288 -162 1.561
SiF2+ Silicon difluoride cation 2 A1 350 259 -91 1.349
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 207 63 0.695
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 341 -115 1.336
FCO+ Carbonyl fluoride cation 3 Π 650 532 -118 1.221
CH3OO methylperoxy radical 12 A" 170 130 -40 1.303
CH2OH Hydroxymethyl radical 9 A 234 417 183 0.562
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 869 -267 1.308
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 156 -108 1.693
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 103 -255 3.460
HCCN cyanomethylene 5 Π 129 -268 -397 -0.480
SO2F2 Sulfuryl fluoride 4 A1 385 317 -68 1.214
SO2F2 Sulfuryl fluoride 5 A2 388 319 -69 1.215
CHCl2 dichloromethyl radical 4 A' 190 297 107 0.639
C4H6 Methylenecyclopropane 17 B1 360 274 -86 1.312
C2Cl2 dichloroacetylene 4 Πg 333 188 -145 1.772
HClO4 perchloric acid 7 A' 548 448 -100 1.223
HClO4 perchloric acid 8 A' 405 330 -75 1.228
HClO4 perchloric acid 11 A" 408 334 -74 1.221
ClFO3 Perchloryl fluoride 3 A1 549 443 -106 1.239
ClFO3 Perchloryl fluoride 5 E 589 483 -106 1.220
ClFO3 Perchloryl fluoride 6 E 405 314 -91 1.290
SOCl2 thionyl chloride 4 A' 194 156 -38 1.243
F2SO Thionyl Fluoride 4 A' 378 296 -81 1.274
SF4 Sulfur tetrafluoride 3 A1 532 431 -101 1.234
SF4 Sulfur tetrafluoride 4 A1 228 177 -51 1.286
SF4 Sulfur tetrafluoride 7 B1 353 284 -69 1.242
BrF3 Bromine trifluoride 3 A1 242 187 -55 1.292
BrF3 Bromine trifluoride 6 B2 350 283 -67 1.237
BrF5 bromine pentafluoride 3 A1 369 281 -88 1.312
BrF5 bromine pentafluoride 8 E 415 332 -83 1.248
ClF3 Chlorine trifluoride 3 A1 328 238 -90 1.376
ClF3 Chlorine trifluoride 6 B2 442 342 -100 1.294
Cl2O Dichlorine monoxide 3 B2 686 547 -139 1.254
NCl3 nitrogen trichloride 3 E 642 515 -127 1.247
PCl5 Phosphorus pentachloride 7 E' 100 82 -18 1.226
OClO- Chlorine dioxide anion 2 A1 418 311 -107 1.344
N2O4 Dinitrogen tetroxide 9 B2u 265 185 -80 1.430
N2O3 Dinitrogen trioxide 9 A" 63 129 66 0.489
SF5 Sulfur pentafluoride 3 A1 554 422 -132 1.313
SF5 Sulfur pentafluoride 8 E 525 418 -107 1.255
SF5 Sulfur pentafluoride 9 E 387 289 -98 1.339
C3O Tricarbon monoxide 5 Π 109 188 79 0.579
Li2O dilithium oxide 3 Πu 112 88 -23 1.264
C3 carbon trimer 3 Πu 63 119 56 0.531
C4 Carbon tetramer 4 Πg 323 241 -82 1.342
ClOOCl Dichlorine dioxide 1 A 750 1128 378 0.665
ClOOCl Dichlorine dioxide 5 B 653 521 -132 1.253
SiH- silicon monohydride anion 1 Σ 2175 1763 -412 1.233
ClONO2 Chlorine nitrate 7 A' 273 217 -56 1.258
OPCl Phosphorus oxychloride 2 A' 308 465 157 0.662
OPCl Phosphorus oxychloride 3 A' 492 279 -213 1.762
H2OH2O water dimer 7 A' 143 212 69 0.676
H2OH2O water dimer 8 A' 103 176 73 0.586
H2OH2O water dimer 11 A" 108 184 76 0.588
H2OH2O water dimer 12 A" 88 146 58 0.601
H2POH Phosphinous acid 9 A" 375 239 -136 1.569
Mg2 Magnesium diatomic 1 Σg 51 103 52 0.498
ClOF3 Chlorine trifluoride oxide 4 A' 482 381 -101 1.267
ClOF3 Chlorine trifluoride oxide 5 A' 319 239 -80 1.333
ClOF3 Chlorine trifluoride oxide 6 A' 224 169 -55 1.325
ClOF3 Chlorine trifluoride oxide 8 A" 499 406 -93 1.228
ClOF3 Chlorine trifluoride oxide 9 A" 412 311 -101 1.327
ZnCH3 Zinc monomethyl 6 E 315 588 273 0.536
ClONO chlorine nitrite 4 A' 406 298 -108 1.362
ClONO chlorine nitrite 5 A' 270 152 -118 1.777
HSO3 HOSO2 3 A 1296 1030 -266 1.258