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 PBEPBE/6-31G(2df,p)
Calculated values were scaled by 0.9897.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 181 68 0.625
CH3CONH2 Acetamide 20 A 259 209 -50 1.241
CH3COOH Acetic acid 18 A" 93 58 -35 1.594
CH3OH Methyl alcohol 12 A" 200 321 121 0.624
CH3COCH3 Acetone 12 A2 77 49 -28 1.583
C2H6O2S Dimethyl sulfone 13 A2 326 268 -58 1.217
C2H6O2S Dimethyl sulfone 20 B1 262 200 -62 1.311
C2H4+ Ethylene cation 4 Au 84 -620 -704 -0.136
C2H2 Acetylene 4 Πg 612 480 -132 1.275
CHONH2 formamide 12 A" 289 124 -165 2.330
CH3COCl Acetyl Chloride 15 A" 166 130 -36 1.277
CBr2F2 Methane, dibromodifluoro- 3 A1 140 327 187 0.428
C2F6 hexafluoroethane 4 A1u 68 50 -18 1.358
C3F8 perfluoropropane 13 A2 276 206 -70 1.343
CF2CCl2 difluorodichloroethylene 7 B1 1327 567 -760 2.341
CF2CCl2 difluorodichloroethylene 8 B1 989 309 -680 3.206
CF2CCl2 difluorodichloroethylene 11 B2 564 442 -122 1.277
CF2CCl2 difluorodichloroethylene 12 B2 323 175 -148 1.842
C3H6O 2-Propen-1-ol 22 A 377 310 -68 1.218
C3H6O 2-Propen-1-ol 24 A 188 114 -74 1.656
CH3OCHO methyl formate 18 A" 130 93 -37 1.394
C5H8 Cyclopentene 18 A' 254 134 -120 1.899
C2H4O3 trioxolane124 21 B 193 154 -39 1.254
C4H4N2 Pyridazine 13 A2 421 343 -78 1.226
C2H2N4 sym-tetrazine 18 B3u 254 103 -151 2.472
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 502 151 0.699
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 335 -874 3.606
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 401 -132 1.330
C6F6 hexafluorobenzene 7 B2g 715 499 -216 1.432
C6F6 hexafluorobenzene 8 B2g 243 177 -66 1.371
C6F6 hexafluorobenzene 20 E2u 175 130 -45 1.344
NH2CN cyanamide 5 A' 408 590 182 0.692
C4H6O2 2,3-Butanedione 9 Ag 614 498 -116 1.232
C4H6O2 2,3-Butanedione 13 Au 1111 896 -215 1.241
C4H6O2 2,3-Butanedione 21 Bg 240 91 -149 2.628
C6H4 Benzyne 24 B2 472 364 -108 1.298
C5H12 Propane, 2,2-dimethyl- 12 T1 203 305 102 0.666
C2H3NO3 Oxamic acid 3 A' 2600 3478 878 0.747
C2H3NO3 Oxamic acid 15 A' 328 254 -74 1.289
C2H3NO3 Oxamic acid 16 A" 984 797 -187 1.234
C2H3NO3 Oxamic acid 17 A" 815 671 -144 1.214
C2H3NO3 Oxamic acid 21 A" 162 71 -91 2.277
C3H6O Oxetane 12 A2 986 801 -185 1.230
C3H6O Oxetane 18 B1 90 33 -56 2.694
C3H6O Oxetane 23 B2 1228 1010 -218 1.216
C3O2 Carbon suboxide 7 Πu 61 88 27 0.692
HCNO fulminic acid 5 Π 224 -277 -501 -0.809
Zn(CH3)2 dimethyl zinc 11 E' 134 96 -38 1.395
C5H8 1,4-Pentadiene 16 A 137 284 147 0.482
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 184 -43 1.234
CH3ONO Methyl nitrite 15 A" 186 142 -44 1.309
C2F2 difluoroacetylene 4 Πg 270 166 -104 1.631
C6H8 (E)-hexa-1,3,5-triene 36 Bu 170 139 -31 1.221
SiF2+ Silicon difluoride cation 2 A1 350 257 -93 1.364
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 206 62 0.698
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 344 -112 1.324
CH3OO methylperoxy radical 12 A" 170 124 -46 1.374
CH3 Methyl radical 2 A2" 606 468 -138 1.295
CH2OH Hydroxymethyl radical 9 A 234 437 203 0.535
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 867 -269 1.311
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 158 -106 1.675
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 105 -253 3.421
CHCl2 dichloromethyl radical 4 A' 190 292 102 0.651
C4H6 Methylenecyclopropane 17 B1 360 284 -76 1.269
HClO4 perchloric acid 12 A" 191 134 -57 1.423
GaF3 Gallium trifluoride 4 E' 192 102 -90 1.877
BrF5 bromine pentafluoride 6 B2 281 218 -63 1.287
CaF2 Calcium difluoride 2 A1 120 93 -27 1.284
ZnCN Zinc monocyanide 3 Π 212 104 -108 2.042
PCl5 Phosphorus pentachloride 2 A1' 370 272 -98 1.360
PCl5 Phosphorus pentachloride 7 E' 100 81 -19 1.234
N2O4 Dinitrogen tetroxide 9 B2u 265 190 -75 1.396
N2O3 Dinitrogen trioxide 9 A" 63 143 80 0.441
SF5 Sulfur pentafluoride 9 E 387 317 -71 1.223
C3 carbon trimer 3 Πu 63 97 33 0.655
CaOH Calcium monohydroxide 2 Σ 353 623 270 0.567
CaOH Calcium monohydroxide 3 Π 609 312 -297 1.952
C4 Carbon tetramer 4 Πg 323 196 -127 1.645
Cu2 Copper dimer 1 Σg 265 429 164 0.617
SiH- silicon monohydride anion 1 Σ 2175 1772 -403 1.227
SF5Cl sulfur chloropentafluoride 5 B1 625 459 -166 1.363
SF5Cl sulfur chloropentafluoride 7 B2 505 305 -200 1.653
SF5Cl sulfur chloropentafluoride 11 E 397 242 -155 1.639
ZnH2 Zinc hydride 3 Πu 633 349 -284 1.813
C2H4O4 Formic acid dimer 13 Au 1050 77 -973 13.584
ClOO chloroperoxy radical 3 A' 201 294 92 0.686
B2H6 Diborane 14 B2u 368 300 -68 1.228
H2POH Phosphinous acid 9 A" 375 243 -132 1.542
Mg2 Magnesium diatomic 1 Σg 51 107 56 0.477
ZnCH3 Zinc monomethyl 6 E 315 575 260 0.548
ClONO chlorine nitrite 4 A' 406 305 -101 1.331
ClONO chlorine nitrite 5 A' 270 163 -107 1.658
CH3BO Borane, methyloxo- 7 E 897 1392 495 0.644
HSO3 HOSO2 3 A 1296 1064 -232 1.218