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 PBEPBEultrafine/6-31G*
Calculated values were scaled by 0.9835.

Species Name mode Symmetry Experiment Theory difference ratio
CH3CONH2 Acetamide 20 A 259 161 -98 1.609
C3H4O2 β–Propiolactone 21 A" 113 179 66 0.633
CH3SeH Methane selenol 12 A" 145 212 67 0.684
C2H6O2S Dimethyl sulfone 20 B1 262 202 -60 1.300
C2H6O2S Dimethyl sulfone 13 A2 326 262 -64 1.243
CH3COOH Acetic acid 18 A" 93 60 -33 1.540
CH3OH Methyl alcohol 12 A" 200 344 144 0.581
CH3COCH3 Acetone 12 A2 77 39 -38 1.964
C2H2 Acetylene 4 Πg 612 445 -167 1.376
CHONH2 formamide 12 A" 289 68 -220 4.230
CH3COCl Acetyl Chloride 15 A" 166 130 -36 1.275
C2F6 hexafluoroethane 4 A1u 68 47 -21 1.452
CH3COCH2CH3 2-Butanone 33 A" 87 19 -68 4.553
CH3COOCH3 methyl acetate 27 A" 110 17 -93 6.455
C5H12 Pentane 23 A2 131 107 -24 1.227
C3H6O 2-Propen-1-ol 24 A 188 113 -75 1.668
C4H8S Thiophene, tetrahydro- 5 A 1464 2954 1490 0.496
C4H8S Thiophene, tetrahydro- 6 A 1441 2954 1513 0.488
C4H8S Thiophene, tetrahydro- 7 A 1321 2939 1618 0.450
C4H8S Thiophene, tetrahydro- 8 A 1276 2938 1662 0.434
C4H8S Thiophene, tetrahydro- 11 A 1023 1437 414 0.712
C4H8S Thiophene, tetrahydro- 12 A 888 1434 546 0.619
C4H8S Thiophene, tetrahydro- 13 A 829 1311 482 0.632
C4H8S Thiophene, tetrahydro- 14 A 822 1286 464 0.639
C4H8S Thiophene, tetrahydro- 15 A 678 1257 579 0.540
C4H8S Thiophene, tetrahydro- 16 A 472 1236 764 0.382
C4H8S Thiophene, tetrahydro- 17 A 290 1195 905 0.243
C2F4 Tetrafluoroethylene 7 B2g 508 413 -95 1.230
C5H8 Cyclopentene 18 A' 254 143 -111 1.775
C2H3N3 1H-1,2,4-Triazole 18 A" 640 520 -120 1.231
C4H4N2 Pyridazine 13 A2 421 341 -80 1.235
C4H2 Diacetylene 8 Πu 630 503 -127 1.253
NH2CN cyanamide 5 A' 408 592 184 0.690
C3H6O Oxetane 18 B1 90 25 -65 3.643
C3O2 Carbon suboxide 7 Πu 61 123 62 0.494
C2H3NO3 Oxamic acid 3 A' 2600 3448 848 0.754
C2H3NO3 Oxamic acid 15 A' 328 253 -75 1.295
C2H3NO3 Oxamic acid 16 A" 984 773 -211 1.272
C2H3NO3 Oxamic acid 21 A" 162 67 -95 2.406
HCNO fulminic acid 5 Π 224 -230 -454 -0.973
C5H8 1,4-Pentadiene 16 A 137 286 149 0.479
C5H8 1,4-Pentadiene 31 B 721 585 -136 1.233
C5H8 1,4-Pentadiene 33 B 331 100 -231 3.320
HCCCl Chloroacetylene 5 Π 326 254 -72 1.283
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 185 -42 1.226
C6H6 Benzvalene 10 A1 996 739 -257 1.348
CH3ONO Methyl nitrite 15 A" 186 144 -42 1.290
C6H8 (E)-hexa-1,3,5-triene 36 Bu 170 139 -31 1.221
H2CS- thioformaldehyde anion 4 B1 450 -147 -597 -3.070
SiF2+ Silicon difluoride cation 2 A1 350 271 -79 1.291
LiOH lithium hydroxide 3 Π 257 205 -51 1.251
C4H6O Cyclobutanone 13 A2 909 590 -319 1.541
C4H6O Cyclobutanone 12 A2 1163 910 -253 1.277
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 211 67 0.681
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 339 -117 1.344
C4H6O Cyclobutanone 20 B1 63 -32 -95 -1.956
FCO+ Carbonyl fluoride cation 3 Π 650 521 -129 1.248
CH3 Methyl radical 2 A2" 606 459 -148 1.323
CH2OH Hydroxymethyl radical 9 A 234 446 212 0.525
HCCN cyanomethylene 5 Π 129 -306 -435 -0.422
CH3OO methylperoxy radical 12 A" 170 137 -33 1.240
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 107 -251 3.334
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 869 -267 1.306
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 163 -101 1.621
CHCl2 dichloromethyl radical 4 A' 190 296 106 0.641
ClFO3 Perchloryl fluoride 6 E 405 319 -86 1.268
C4H6 Methylenecyclopropane 17 B1 360 272 -88 1.323
MgF2 Magnesium fluoride 3 Πu 165 132 -33 1.249
HSO3F Fluorosulfonic acid 11 A 390 314 -76 1.243
Cl2O Dichlorine monoxide 3 B2 686 550 -136 1.248
ClF3 Chlorine trifluoride 3 A1 328 257 -71 1.278
ClF3 Chlorine trifluoride 6 B2 442 354 -88 1.250
SOCl2 thionyl chloride 4 A' 194 157 -37 1.233
OClO- Chlorine dioxide anion 2 A1 418 319 -99 1.309
SF4 Sulfur tetrafluoride 4 A1 228 171 -57 1.334
F2SO Thionyl Fluoride 4 A' 378 305 -73 1.238
BrF3 Bromine trifluoride 3 A1 242 193 -49 1.252
C2Cl2 dichloroacetylene 4 Πg 333 201 -132 1.656
S8 Octasulfur 3 B1 411 311 -100 1.320
S8 Octasulfur 10 E3 437 357 -80 1.223
N2O3 Dinitrogen trioxide 9 A" 63 139 76 0.454
C3O Tricarbon monoxide 5 Π 109 177 68 0.615
PCl5 Phosphorus pentachloride 7 E' 100 82 -18 1.226
ClOOCl Dichlorine dioxide 1 A 750 1163 413 0.645
ClOOCl Dichlorine dioxide 5 B 653 523 -130 1.249
SF5 Sulfur pentafluoride 3 A1 554 439 -114 1.261
SF5 Sulfur pentafluoride 9 E 387 296 -91 1.308
N2O4 Dinitrogen tetroxide 9 B2u 265 187 -78 1.416
SiH- silicon monohydride anion 1 Σ 2175 1734 -441 1.255
C3 carbon trimer 3 Πu 63 109 46 0.581
C4 Carbon tetramer 4 Πg 323 210 -113 1.537
NCl3 nitrogen trichloride 3 E 642 515 -127 1.246
OPCl Phosphorus oxychloride 2 A' 308 469 161 0.656
OPCl Phosphorus oxychloride 3 A' 492 279 -213 1.763
H2OH2O water dimer 6 A' 311 493 182 0.631
H2OH2O water dimer 7 A' 143 250 107 0.573
H2OH2O water dimer 11 A" 108 188 80 0.574
H2OH2O water dimer 12 A" 88 -134 -222 -0.655
H2POH Phosphinous acid 9 A" 375 233 -142 1.610
Mg2 Magnesium diatomic 1 Σg 51 103 52 0.496
ClOF3 Chlorine trifluoride oxide 6 A' 224 170 -54 1.314
ClONO chlorine nitrite 4 A' 406 309 -97 1.313
ClONO chlorine nitrite 5 A' 270 158 -112 1.708
ZnCN Zinc monocyanide 3 Π 212 -87 -299 -2.425
B2H6 Diborane 14 B2u 369 294 -75 1.254