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/3-21G*
Calculated values were scaled by 0.9535.

Species Name mode Symmetry Experiment Theory difference ratio
CH3CONH2 Acetamide 20 A 259 383 125 0.675
CH3COOH Acetic acid 11 A' 657 517 -140 1.271
CH3COOH Acetic acid 18 A" 93 70 -23 1.337
CH3OH Methyl alcohol 12 A" 200 380 180 0.527
C2H6O2S Dimethyl sulfone 13 A2 326 249 -77 1.312
C2H4+ Ethylene cation 4 Au 84 -625 -709 -0.135
CHONH2 formamide 12 A" 289 456 168 0.633
HNCO Isocyanic acid 4 A' 777 572 -204 1.357
CCl2O Phosgene 5 B2 849 670 -179 1.267
CBr2F2 Methane, dibromodifluoro- 3 A1 140 305 165 0.458
CFCl3 Trichloromonofluoromethane 4 E 847 669 -178 1.265
CF2Cl2 difluorodichloromethane 6 B1 902 713 -189 1.265
C3F8 perfluoropropane 13 A2 276 191 -85 1.442
CHOCH(CH3)CH3 Propanal, 2-methyl- 16 A' 632 501 -131 1.261
CF2CCl2 difluorodichloroethylene 7 B1 1327 582 -745 2.279
CF2CCl2 difluorodichloroethylene 8 B1 989 308 -681 3.212
CF2CCl2 difluorodichloroethylene 11 B2 564 429 -135 1.314
CF2CCl2 difluorodichloroethylene 12 B2 323 170 -153 1.900
C3H6O 2-Propen-1-ol 22 A 377 287 -90 1.315
C3H6O 2-Propen-1-ol 24 A 188 99 -89 1.893
C2H2O2 Ethanedial 7 Au 127 187 60 0.678
CH3OCHO methyl formate 18 A" 130 30 -100 4.321
CH3CH2CHO Propanal 24 A" 135 101 -34 1.332
C4H9N Pyrrolidine 36 A" 65 39 -26 1.655
C4H8O2 1,4-Dioxane 19 Au 288 214 -74 1.348
C5H8 Cyclopentene 18 A' 254 121 -133 2.105
CH2N4 1H-Tetrazole 10 A' 969 765 -204 1.266
CH2N4 1H-Tetrazole 11 A' 925 697 -228 1.326
C2H4O3 trioxolane124 21 B 193 146 -47 1.325
C4H4N2 Pyridazine 13 A2 421 325 -96 1.296
C2H2N4 sym-tetrazine 5 Au 335 241 -94 1.390
C2H2N4 sym-tetrazine 13 B2u 883 666 -217 1.325
C2H2N4 sym-tetrazine 18 B3u 254 41 -213 6.139
N2H4 Hydrazine 6 A 780 569 -211 1.371
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 531 180 0.662
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 338 -871 3.580
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 368 -165 1.449
C6F6 hexafluorobenzene 8 B2g 243 177 -66 1.370
C6F6 hexafluorobenzene 20 E2u 175 128 -47 1.369
C4H6O2 2,3-Butanedione 16 Au 48 -44 -92 -1.103
C4H6O2 2,3-Butanedione 21 Bg 240 -27 -267 -9.030
C2N2 Cyanogen 4 Πg 503 752 249 0.669
Cl2CS Thiophosgene 5 B2 816 647 -169 1.262
C5H12 Propane, 2,2-dimethyl- 12 T1 203 319 116 0.636
C2H3NO3 Oxamic acid 3 A' 2600 3185 585 0.816
C2H3NO3 Oxamic acid 15 A' 328 240 -88 1.364
C2H3NO3 Oxamic acid 17 A" 815 642 -173 1.269
C2H3NO3 Oxamic acid 21 A" 162 113 -49 1.437
C3H6O Oxetane 7 A1 1018 802 -216 1.270
C3H6O Oxetane 23 B2 1228 911 -317 1.348
C3O2 Carbon suboxide 7 Πu 61 146 85 0.417
HCNO fulminic acid 5 Π 224 489 265 0.458
Zn(CH3)2 dimethyl zinc 11 E' 134 -117 -251 -1.148
C5H8 1,4-Pentadiene 16 A 137 290 153 0.472
C5H8 1,4-Pentadiene 17 A 102 76 -26 1.337
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 180 -47 1.264
CH3ONO Methyl nitrite 15 A" 186 126 -60 1.476
CH3NO nitrosomethane 7 A' 842 663 -179 1.270
C4N2 2-Butynedinitrile 6 Πg 504 902 398 0.559
C4N2 2-Butynedinitrile 8 Πu 472 682 210 0.692
LiOH lithium hydroxide 3 Π 257 376 120 0.682
NaOH sodium hydroxide 3 Π 300 122 -178 2.449
SiF2+ Silicon difluoride cation 2 A1 350 256 -94 1.366
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 213 69 0.676
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 327 -129 1.394
CCl2 dichloromethylene 3 B2 758 556 -202 1.362
FCO+ Carbonyl fluoride cation 3 Π 650 476 -174 1.367
C2H Ethynyl radical 3 Π 372 269 -102 1.379
CH3OO methylperoxy radical 12 A" 170 130 -40 1.305
CH3 Methyl radical 2 A2" 606 462 -144 1.312
CH2OH Hydroxymethyl radical 9 A 234 412 178 0.568
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 842 -294 1.349
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 149 -115 1.769
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 99 -259 3.620
ClNO Nitrosyl chloride 1 A' 1800 1426 -373 1.262
OH- hydroxide anion 1 Σ 3738 2538 -1201 1.473
HClO4 perchloric acid 8 A' 405 321 -84 1.263
HClO4 perchloric acid 12 A" 191 81 -110 2.351
ClFO3 Perchloryl fluoride 6 E 405 316 -89 1.282
HF Hydrogen fluoride 1 Σ 4138 3356 -782 1.233
NH3 Ammonia 2 A1 950 724 -226 1.312
H2SO4 Sulfuric acid 8 A 224 133 -91 1.683
H2SO4 Sulfuric acid 15 B 288 211 -77 1.365
HNO3 Nitric acid 7 A' 579 441 -138 1.312
SOCl2 thionyl chloride 4 A' 194 152 -42 1.275
SOCl2 thionyl chloride 5 A" 455 357 -98 1.274
H2O2 Hydrogen peroxide 4 A 371 6 -365 63.745
CuCl Copper monochloride 1 Σ 418 319 -99 1.311
O2+ diatomic oxygen cation 1 Σg 1906 1299 -607 1.467
F2O Difluorine monoxide 2 A1 461 351 -110 1.313
F2SO Thionyl Fluoride 4 A' 378 292 -86 1.295
FOOF Perfluoroperoxide 1 A 1210 901 -309 1.344
NF3 Nitrogen trifluoride 2 A1 647 479 -168 1.352
NF3 Nitrogen trifluoride 4 E 492 349 -143 1.409
SF4 Sulfur tetrafluoride 4 A1 228 177 -51 1.286
AsF5 Arsenic pentafluoride 7 E' 123 92 -31 1.334
BeF2 Beryllium fluoride 3 Πu 343 248 -95 1.384
BrF3 Bromine trifluoride 3 A1 242 185 -57 1.310
BrF3 Bromine trifluoride 6 B2 350 272 -78 1.287
HSO3F Fluorosulfonic acid 12 A 266 200 -66 1.332
FNO Nitrosyl fluoride 1 A' 1844 1398 -446 1.319
FNO3 Fluorine nitrate 7 A' 303 218 -85 1.388
FNO3 Fluorine nitrate 8 A" 709 557 -152 1.274
BrF5 bromine pentafluoride 3 A1 369 289 -80 1.275
BrF5 bromine pentafluoride 6 B2 281 173 -108 1.623
BrF5 bromine pentafluoride 8 E 415 321 -94 1.294
ClF3 Chlorine trifluoride 1 A1 752 595 -157 1.263
ClF3 Chlorine trifluoride 3 A1 328 197 -131 1.663
ClF3 Chlorine trifluoride 6 B2 442 283 -159 1.561
Cl2O Dichlorine monoxide 3 B2 686 525 -161 1.308
SO2Cl2 Sulfuryl chloride 3 A1 408 323 -85 1.263
SO2Cl2 Sulfuryl chloride 7 B1 388 300 -88 1.292
S2Cl2 Disulfur dichloride 2 A 466 354 -112 1.316
S2Cl2 Disulfur dichloride 5 B 461 339 -122 1.361
NCl3 nitrogen trichloride 3 E 642 473 -169 1.357
PCl5 Phosphorus pentachloride 2 A1' 370 243 -127 1.525
O3 Ozone 2 A1 705 518 -187 1.361
NO Nitric oxide 1 Σ 1904 1477 -427 1.289
NO2 Nitrogen dioxide 1 A1 1318 1026 -292 1.284
NO2 Nitrogen dioxide 3 B2 1618 1235 -383 1.311
S8 Octasulfur 3 B1 411 272 -139 1.509
S8 Octasulfur 10 E3 437 325 -112 1.347
N2O4 Dinitrogen tetroxide 5 B1u 1261 1000 -261 1.261
N2O4 Dinitrogen tetroxide 9 B2u 265 144 -121 1.836
N2O3 Dinitrogen trioxide 1 A' 1832 1433 -399 1.279
N2O3 Dinitrogen trioxide 9 A" 63 142 79 0.443
SF5 Sulfur pentafluoride 3 A1 554 431 -123 1.285
SF5 Sulfur pentafluoride 8 E 525 417 -108 1.260
SF5 Sulfur pentafluoride 9 E 387 280 -107 1.381
NaK Sodium Potassium 1 Σ 124 96 -28 1.292
Li2O dilithium oxide 3 Πu 112 50 -61 2.212
C3 carbon trimer 3 Πu 63 40 -24 1.591
CaOH Calcium monohydroxide 2 Σ 353 609 257 0.579
CaOH Calcium monohydroxide 3 Π 609 413 -196 1.473
BrNO Nitrosyl bromide 1 A' 1832 1383 -450 1.325
CuH Copper monohydride 1 Σ 1941 1247 -694 1.557
ND3 Ammonia-d3 2 A1 748 552 -196 1.356
NH2- amino anion 1 A1 3122 2451 -671 1.274
NH2- amino anion 3 B2 3190 2493 -698 1.280
SiH- silicon monohydride anion 1 Σ 2175 1717 -458 1.267
N2F2 Dinitrogen difluoride, (E)- 1 Ag 1523 1097 -426 1.388
N2F2 Dinitrogen difluoride, (E)- 6 Bu 423 330 -93 1.282
SF5Cl sulfur chloropentafluoride 5 B1 625 420 -205 1.486
SF5Cl sulfur chloropentafluoride 7 B2 505 276 -229 1.829
SF5Cl sulfur chloropentafluoride 11 E 397 215 -182 1.848
H3O+ hydronium cation 2 A1 954 408 -546 2.339
DF Hydrofluoric acid-d 1 Σ 2998 2432 -566 1.233
C2H4O4 Formic acid dimer 2 Ag 2949 1674 -1275 1.762
C2H4O4 Formic acid dimer 6 Ag 1214 826 -388 1.470
C2H4O4 Formic acid dimer 13 Au 1050 92 -958 11.442
C2H4O4 Formic acid dimer 18 Bu 2939 1864 -1075 1.577
C2H4O4 Formic acid dimer 24 Bu 268 485 217 0.552
ClONO2 Chlorine nitrate 7 A' 273 197 -77 1.390
ClONO2 Chlorine nitrate 8 A" 711 558 -153 1.274
Na2 Sodium diatomic 1 Σg 159 265 106 0.600
H2POH Phosphinous acid 9 A" 375 181 -195 2.078
Mg2 Magnesium diatomic 1 Σg 51 130 79 0.392
ClOF3 Chlorine trifluoride oxide 4 A' 482 367 -115 1.314
ClOF3 Chlorine trifluoride oxide 5 A' 319 219 -100 1.458
ClOF3 Chlorine trifluoride oxide 6 A' 224 161 -63 1.388
ClOF3 Chlorine trifluoride oxide 8 A" 499 387 -112 1.289
ClOF3 Chlorine trifluoride oxide 9 A" 412 290 -122 1.423
BrONO2 Bromine nitrate 8 A" 728 559 -169 1.302
ZnCH3 Zinc monomethyl 6 E 315 626 311 0.503
ClONO chlorine nitrite 1 A' 1715 1336 -379 1.284
ClONO chlorine nitrite 5 A' 270 182 -88 1.485
CH3BO Borane, methyloxo- 7 E 897 1409 512 0.637
BrONO Bromine nitrite 1 A' 1723 1363 -361 1.265
HSO3 HOSO2 3 A 1296 984 -312 1.317
ONONO Nitrosyl nitrite 6 B1 140 105 -35 1.332
ONONO Nitrosyl nitrite 7 B2 1697 1335 -362 1.271