return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) 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 BLYP/6-31G(2df,p)
Calculated values were scaled by 0.9945.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 182 69 0.619
CH3COOH Acetic acid 18 A" 93 61 -32 1.519
CH3OH Methyl alcohol 12 A" 200 322 122 0.622
C2H6O2S Dimethyl sulfone 13 A2 326 267 -59 1.220
C2H6O2S Dimethyl sulfone 20 B1 262 197 -65 1.330
C2H4+ Ethylene cation 4 Au 84 -583 -667 -0.144
C2H2 Acetylene 4 Πg 612 442 -170 1.384
CHONH2 formamide 12 A" 289 86 -203 3.363
CH3CHClCH3 Propane, 2-chloro- 27 A" 276 227 -49 1.214
CH3COCl Acetyl Chloride 15 A" 166 131 -35 1.272
CBr2F2 Methane, dibromodifluoro- 3 A1 140 311 171 0.450
C2F6 hexafluoroethane 4 A1u 68 51 -17 1.323
C3F8 perfluoropropane 13 A2 276 210 -66 1.315
CHOCH(CH3)CH3 Propanal, 2-methyl- 16 A' 632 521 -111 1.212
CF2CCl2 difluorodichloroethylene 7 B1 1327 560 -767 2.369
CF2CCl2 difluorodichloroethylene 8 B1 989 305 -684 3.246
CF2CCl2 difluorodichloroethylene 11 B2 564 436 -128 1.293
CF2CCl2 difluorodichloroethylene 12 B2 323 178 -145 1.816
C3H6O 2-Propen-1-ol 24 A 188 112 -76 1.672
CH3OCHO methyl formate 18 A" 130 93 -37 1.397
C4H8O Furan, tetrahydro- 17 A 286 236 -50 1.214
C4H8O2 1,4-Dioxane 19 Au 288 235 -53 1.227
C5H8 Cyclopentene 18 A' 254 123 -131 2.062
C2H3N3 1H-1,2,4-Triazole 18 A" 640 516 -124 1.241
C2H4O3 trioxolane124 21 B 193 153 -40 1.261
C2H2N4 sym-tetrazine 18 B3u 254 151 -103 1.684
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 331 -878 3.656
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 395 -138 1.350
C6F6 hexafluorobenzene 7 B2g 715 484 -231 1.476
C6F6 hexafluorobenzene 8 B2g 243 177 -66 1.377
C6F6 hexafluorobenzene 20 E2u 175 130 -45 1.345
NH2CN cyanamide 5 A' 408 598 190 0.682
C4H6O2 2,3-Butanedione 9 Ag 614 496 -118 1.237
C4H6O2 2,3-Butanedione 13 Au 1111 918 -193 1.211
C4H6O2 2,3-Butanedione 21 Bg 240 99 -141 2.424
C4H2 Diacetylene 8 Πu 630 516 -114 1.221
C6H4 Benzyne 24 B2 472 367 -105 1.286
C5H12 Propane, 2,2-dimethyl- 12 T1 203 300 97 0.677
C2H3NO3 Oxamic acid 3 A' 2600 3472 872 0.749
C2H3NO3 Oxamic acid 15 A' 328 257 -71 1.276
C2H3NO3 Oxamic acid 16 A" 984 793 -191 1.241
C2H3NO3 Oxamic acid 17 A" 815 664 -151 1.227
C2H3NO3 Oxamic acid 21 A" 162 67 -95 2.406
C3H6O Oxetane 12 A2 986 809 -177 1.219
C3H6O Oxetane 18 B1 90 64 -26 1.407
C3H6O Oxetane 23 B2 1228 971 -257 1.264
C3O2 Carbon suboxide 7 Πu 61 90 29 0.679
HCNO fulminic acid 5 Π 224 -295 -519 -0.761
Zn(CH3)2 dimethyl zinc 11 E' 134 91 -43 1.474
C5H8 1,4-Pentadiene 16 A 137 289 152 0.475
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 185 -42 1.226
CH3ONO Methyl nitrite 15 A" 186 132 -54 1.405
C2F2 difluoroacetylene 4 Πg 270 36 -234 7.484
SiF2+ Silicon difluoride cation 2 A1 350 257 -93 1.362
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 208 64 0.693
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 350 -106 1.303
CH3OO methylperoxy radical 12 A" 170 123 -47 1.383
CH3 Methyl radical 2 A2" 606 469 -138 1.293
C4H9N Cyclobutylamine 21 A' 174 130 -44 1.341
CH2OH Hydroxymethyl radical 9 A 234 444 210 0.527
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 865 -271 1.313
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 157 -107 1.680
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 106 -252 3.391
CH3CO Acetyl radical 4 A' 1420 3020 1600 0.470
OH- hydroxide anion 1 Σ 3738 3319 -419 1.126
CHCl2 dichloromethyl radical 4 A' 190 288 98 0.660
C4H6 Methylenecyclopropane 17 B1 360 287 -73 1.257
HClO4 perchloric acid 12 A" 191 133 -58 1.438
SOCl2 thionyl chloride 4 A' 194 157 -37 1.233
GaF3 Gallium trifluoride 4 E' 192 106 -86 1.806
BrF5 bromine pentafluoride 6 B2 281 208 -73 1.348
CaF2 Calcium difluoride 2 A1 120 95 -25 1.261
ClF3 Chlorine trifluoride 3 A1 328 251 -77 1.308
ClF3 Chlorine trifluoride 6 B2 442 354 -88 1.248
Cl2O Dichlorine monoxide 3 B2 686 536 -150 1.279
SO2Cl2 Sulfuryl chloride 4 A1 218 178 -40 1.222
ZnCN Zinc monocyanide 3 Π 212 105 -107 2.015
NCl3 nitrogen trichloride 3 E 642 505 -137 1.272
PCl5 Phosphorus pentachloride 2 A1' 370 254 -116 1.456
PCl5 Phosphorus pentachloride 7 E' 100 78 -22 1.281
N2O4 Dinitrogen tetroxide 9 B2u 265 173 -92 1.533
N2O3 Dinitrogen trioxide 9 A" 63 140 77 0.450
SF5 Sulfur pentafluoride 9 E 387 307 -80 1.260
Li2O dilithium oxide 3 Πu 112 160 48 0.697
C3 carbon trimer 3 Πu 63 162 99 0.391
CaOH Calcium monohydroxide 2 Σ 353 618 265 0.571
CaOH Calcium monohydroxide 3 Π 609 310 -299 1.962
C4 Carbon tetramer 4 Πg 323 259 -64 1.247
Cu2 Copper dimer 1 Σg 265 427 162 0.620
SiH- silicon monohydride anion 1 Σ 2175 1753 -422 1.241
SF5Cl sulfur chloropentafluoride 5 B1 625 451 -174 1.387
SF5Cl sulfur chloropentafluoride 7 B2 505 299 -206 1.690
SF5Cl sulfur chloropentafluoride 11 E 397 235 -162 1.691
ZnH2 Zinc hydride 3 Πu 633 355 -278 1.782
C2H4O4 Formic acid dimer 13 Au 1050 76 -974 13.737
ClONO2 Chlorine nitrate 7 A' 273 215 -59 1.273
Cl3- trichloride anion 2 Σu 327 270 -57 1.212
H2OH2O water dimer 7 A' 143 213 70 0.673
H2OH2O water dimer 8 A' 103 150 47 0.687
H2OH2O water dimer 11 A" 108 173 65 0.626
H2OH2O water dimer 12 A" 88 -98 -186 -0.902
H2POH Phosphinous acid 9 A" 375 237 -138 1.581
ClOF3 Chlorine trifluoride oxide 5 A' 319 258 -61 1.237
ClOF3 Chlorine trifluoride oxide 6 A' 224 184 -40 1.218
ClOF3 Chlorine trifluoride oxide 9 A" 412 336 -76 1.226
BrONO2 Bromine nitrate 5 A' 564 456 -108 1.237
ZnCH3 Zinc monomethyl 6 E 315 579 264 0.544
ClONO chlorine nitrite 4 A' 406 278 -128 1.458
ClONO chlorine nitrite 5 A' 270 155 -115 1.739
CH3BO Borane, methyloxo- 7 E 897 1415 518 0.634
HSO3 HOSO2 3 A 1296 1065 -231 1.217