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**
Calculated values were scaled by 0.9863.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 178 65 0.634
CH3CONH2 Acetamide 20 A 259 75 -183 3.428
CH3COOH Acetic acid 18 A" 93 63 -30 1.477
CH3OH Methyl alcohol 12 A" 200 333 133 0.600
C2H6O2S Dimethyl sulfone 13 A2 326 261 -65 1.248
C2H6O2S Dimethyl sulfone 20 B1 262 208 -54 1.263
C2H4+ Ethylene cation 4 Au 84 -610 -694 -0.138
C2H2 Acetylene 4 Πg 612 480 -132 1.275
CHONH2 formamide 12 A" 289 151 -138 1.909
CH3COCl Acetyl Chloride 15 A" 166 126 -40 1.314
CBr2F2 Methane, dibromodifluoro- 3 A1 140 313 173 0.447
C2F6 hexafluoroethane 4 A1u 68 43 -25 1.586
C3F8 perfluoropropane 13 A2 276 205 -71 1.346
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 61 -14 1.232
CF2CCl2 difluorodichloroethylene 7 B1 1327 541 -786 2.453
CF2CCl2 difluorodichloroethylene 8 B1 989 309 -680 3.196
CF2CCl2 difluorodichloroethylene 11 B2 564 436 -128 1.292
CF2CCl2 difluorodichloroethylene 12 B2 323 178 -145 1.819
C3H6O 2-Propen-1-ol 24 A 188 114 -74 1.653
CH3OCHO methyl formate 18 A" 130 97 -33 1.336
C2F4 Tetrafluoroethylene 7 B2g 508 414 -94 1.227
C5H8 Cyclopentene 18 A' 254 140 -114 1.818
C2H4O3 trioxolane124 21 B 193 155 -38 1.245
C4H4N2 Pyridazine 13 A2 421 340 -81 1.236
C2H2N4 sym-tetrazine 5 Au 335 269 -66 1.244
C2H2N4 sym-tetrazine 18 B3u 254 109 -145 2.328
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 330 -879 3.665
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 398 -135 1.339
C6F6 hexafluorobenzene 7 B2g 715 466 -249 1.534
C6F6 hexafluorobenzene 8 B2g 243 174 -69 1.393
C6F6 hexafluorobenzene 20 E2u 175 129 -46 1.358
C4H6O2 2,3-Butanedione 9 Ag 614 497 -117 1.235
C4H6O2 2,3-Butanedione 13 Au 1111 899 -212 1.236
C4H6O2 2,3-Butanedione 21 Bg 240 87 -153 2.751
C5H12 Propane, 2,2-dimethyl- 12 T1 203 312 109 0.652
C2H3NO3 Oxamic acid 3 A' 2600 3466 866 0.750
C2H3NO3 Oxamic acid 15 A' 328 256 -72 1.283
C2H3NO3 Oxamic acid 16 A" 984 774 -210 1.272
C2H3NO3 Oxamic acid 21 A" 162 71 -91 2.286
C3H6O Oxetane 12 A2 986 809 -177 1.218
C3H6O Oxetane 18 B1 90 -14 -104 -6.504
C3O2 Carbon suboxide 7 Πu 61 123 62 0.495
HCNO fulminic acid 5 Π 224 -217 -441 -1.031
C5H8 1,4-Pentadiene 16 A 137 286 149 0.479
HCCCl Chloroacetylene 5 Π 326 266 -60 1.227
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 185 -42 1.228
CH3ONO Methyl nitrite 15 A" 186 136 -50 1.365
GeO2 Germanium dioxide 3 Πu 196 160 -35 1.222
LiOH lithium hydroxide 3 Π 257 205 -51 1.250
SiF2+ Silicon difluoride cation 2 A1 350 272 -78 1.287
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 208 64 0.693
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 340 -116 1.339
FCO+ Carbonyl fluoride cation 3 Π 650 523 -127 1.244
CH3OO methylperoxy radical 12 A" 170 130 -40 1.310
CH3 Methyl radical 2 A2" 606 462 -144 1.311
CH2OH Hydroxymethyl radical 9 A 234 436 202 0.536
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 870 -266 1.306
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 157 -107 1.676
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 105 -253 3.421
CHCl2 dichloromethyl radical 4 A' 190 297 107 0.639
C4H6 Methylenecyclopropane 17 B1 360 274 -86 1.314
C2Cl2 dichloroacetylene 4 Πg 333 202 -131 1.651
HClO4 perchloric acid 12 A" 191 132 -59 1.449
ClFO3 Perchloryl fluoride 6 E 405 320 -85 1.266
SOCl2 thionyl chloride 4 A' 194 158 -36 1.228
MgF2 Magnesium fluoride 3 Πu 165 133 -32 1.241
F2SO Thionyl Fluoride 4 A' 378 306 -71 1.233
SF4 Sulfur tetrafluoride 4 A1 228 171 -57 1.335
BrF3 Bromine trifluoride 3 A1 242 196 -46 1.234
BrF5 bromine pentafluoride 6 B2 281 188 -93 1.491
BrF5 bromine pentafluoride 8 E 415 340 -75 1.219
ClF3 Chlorine trifluoride 3 A1 328 259 -69 1.268
ClF3 Chlorine trifluoride 6 B2 442 356 -86 1.243
Cl2O Dichlorine monoxide 3 B2 686 551 -135 1.244
NCl3 nitrogen trichloride 3 E 642 513 -129 1.251
PCl5 Phosphorus pentachloride 2 A1' 370 259 -111 1.426
PCl5 Phosphorus pentachloride 7 E' 100 82 -18 1.226
N2O4 Dinitrogen tetroxide 9 B2u 265 189 -76 1.403
N2O3 Dinitrogen trioxide 9 A" 63 140 77 0.449
SF5 Sulfur pentafluoride 3 A1 554 440 -113 1.257
SF5 Sulfur pentafluoride 8 E 525 430 -94 1.219
SF5 Sulfur pentafluoride 9 E 387 296 -91 1.309
C3 carbon trimer 3 Πu 63 110 46 0.579
CaOH Calcium monohydroxide 2 Σ 353 601 248 0.587
CaOH Calcium monohydroxide 3 Π 609 293 -316 2.079
C4 Carbon tetramer 4 Πg 323 209 -114 1.547
Cu2 Copper dimer 1 Σg 265 411 146 0.644
SiH- silicon monohydride anion 1 Σ 2175 1742 -433 1.249
SF5Cl sulfur chloropentafluoride 5 B1 625 431 -194 1.451
SF5Cl sulfur chloropentafluoride 7 B2 505 287 -218 1.759
SF5Cl sulfur chloropentafluoride 11 E 397 225 -172 1.761
ZnH2 Zinc hydride 3 Πu 633 464 -169 1.364
C2H4O4 Formic acid dimer 13 Au 1050 79 -971 13.354
ClONO2 Chlorine nitrate 7 A' 273 222 -51 1.232
H2OH2O water dimer 6 A' 311 475 164 0.654
H2OH2O water dimer 7 A' 143 236 93 0.605
H2OH2O water dimer 11 A" 108 186 78 0.582
H2OH2O water dimer 12 A" 88 -117 -205 -0.754
H2POH Phosphinous acid 9 A" 375 230 -146 1.634
Mg2 Magnesium diatomic 1 Σg 51 103 52 0.497
ClOF3 Chlorine trifluoride oxide 6 A' 224 171 -53 1.307
ZnCH3 Zinc monomethyl 6 E 315 601 286 0.524
ClONO chlorine nitrite 4 A' 406 299 -107 1.359
ClONO chlorine nitrite 5 A' 270 158 -112 1.711
CH3BO Borane, methyloxo- 7 E 897 1404 507 0.639
HSO3 HOSO2 3 A 1296 1049 -247 1.236