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 LSDA/6-311G**
Calculated values were scaled by 0.9877.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 184 71 0.614
CH3COOH Acetic acid 18 A" 93 75 -18 1.236
CH3OH Methyl alcohol 12 A" 200 332 132 0.602
C2H6O2S Dimethyl sulfone 20 B1 262 212 -50 1.235
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 320 106 0.669
C2H4+ Ethylene cation 4 Au 84 -860 -945 -0.098
CH3COCl Acetyl Chloride 15 A" 166 136 -30 1.223
CBr2F2 Methane, dibromodifluoro- 3 A1 140 334 194 0.420
C2F6 hexafluoroethane 4 A1u 68 43 -25 1.589
C3F8 perfluoropropane 13 A2 276 206 -70 1.337
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 60 -15 1.252
CF2CCl2 difluorodichloroethylene 7 B1 1327 590 -737 2.250
CF2CCl2 difluorodichloroethylene 8 B1 989 318 -671 3.113
CF2CCl2 difluorodichloroethylene 11 B2 564 449 -115 1.257
CF2CCl2 difluorodichloroethylene 12 B2 323 174 -149 1.853
C3H6O 2-Propen-1-ol 22 A 377 309 -68 1.221
C3H6O 2-Propen-1-ol 24 A 188 120 -68 1.562
CH3OCHO methyl formate 18 A" 130 86 -44 1.516
C5H8 Cyclopentene 18 A' 254 168 -86 1.512
C4H4N2 Pyridazine 13 A2 421 337 -84 1.249
C2H2N4 sym-tetrazine 5 Au 335 262 -73 1.278
C2H2N4 sym-tetrazine 18 B3u 254 -27 -281 -9.512
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 534 183 0.657
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 332 -877 3.647
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 412 -121 1.293
C6F6 hexafluorobenzene 8 B2g 243 177 -66 1.374
C6F6 hexafluorobenzene 20 E2u 175 131 -44 1.331
C4H6O2 2,3-Butanedione 13 Au 1111 876 -235 1.268
C4H6O2 2,3-Butanedione 16 Au 48 -34 -82 -1.409
C4H6O2 2,3-Butanedione 21 Bg 240 49 -191 4.862
C5H12 Propane, 2,2-dimethyl- 12 T1 203 325 122 0.625
C2H3NO3 Oxamic acid 3 A' 2600 3432 832 0.758
C2H3NO3 Oxamic acid 15 A' 328 259 -69 1.268
C2H3NO3 Oxamic acid 21 A" 162 87 -75 1.865
C3H6O Oxetane 12 A2 986 809 -177 1.219
C3H6O Oxetane 18 B1 90 -6 -95 -16.322
C3O2 Carbon suboxide 7 Πu 61 95 34 0.643
HCNO fulminic acid 5 Π 224 152 -72 1.475
C5H8 1,4-Pentadiene 16 A 137 291 154 0.471
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 182 -45 1.246
CH3SSCH3 Disulfide, dimethyl 13 A 117 86 -31 1.356
C6H8 (E)-hexa-1,3,5-triene 36 Bu 170 138 -32 1.229
LiOH lithium hydroxide 3 Π 257 373 117 0.687
SiF2+ Silicon difluoride cation 2 A1 350 262 -88 1.333
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 218 74 0.661
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 342 -114 1.333
C2H Ethynyl radical 3 Π 372 279 -93 1.333
CH3OO methylperoxy radical 12 A" 170 137 -33 1.241
CH2OH Hydroxymethyl radical 9 A 234 381 147 0.614
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 876 -260 1.297
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 162 -102 1.631
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 106 -252 3.373
CHCl2 dichloromethyl radical 4 A' 190 272 82 0.698
C4H6 Methylenecyclopropane 17 B1 360 279 -81 1.291
C2Cl2 dichloroacetylene 4 Πg 333 252 -81 1.320
HClO4 perchloric acid 12 A" 191 154 -37 1.240
SF4 Sulfur tetrafluoride 4 A1 228 187 -41 1.218
BrF3 Bromine trifluoride 3 A1 242 198 -44 1.221
BrF5 bromine pentafluoride 6 B2 281 193 -88 1.455
ClF3 Chlorine trifluoride 3 A1 328 257 -71 1.277
ClF3 Chlorine trifluoride 6 B2 442 355 -87 1.246
ZnCl Zinc monochloride 1 Σ 391 289 -101 1.350
PCl5 Phosphorus pentachloride 2 A1' 370 264 -106 1.402
S8 Octasulfur 3 B1 411 316 -95 1.300
N2O4 Dinitrogen tetroxide 9 B2u 265 217 -48 1.221
N2O3 Dinitrogen trioxide 9 A" 63 155 92 0.407
SF5 Sulfur pentafluoride 3 A1 554 453 -101 1.222
SF5 Sulfur pentafluoride 9 E 387 304 -84 1.275
C3 carbon trimer 3 Πu 63 -82 -145 -0.775
SiH- silicon monohydride anion 1 Σ 2175 1761 -414 1.235
SF5Cl sulfur chloropentafluoride 5 B1 625 443 -182 1.410
SF5Cl sulfur chloropentafluoride 7 B2 505 299 -206 1.691
SF5Cl sulfur chloropentafluoride 11 E 397 236 -161 1.680
H3O+ hydronium cation 2 A1 954 677 -278 1.410
C2H4O4 Formic acid dimer 2 Ag 2949 2038 -911 1.447
C2H4O4 Formic acid dimer 13 Au 1050 80 -970 13.071
C2H4O4 Formic acid dimer 18 Bu 2939 2269 -669 1.295
C2H4O4 Formic acid dimer 24 Bu 268 444 176 0.603
ClOO chloroperoxy radical 3 A' 201 312 111 0.646
B2H6 Diborane 14 B2u 368 268 -100 1.374
H2OH2O water dimer 6 A' 311 460 149 0.677
H2OH2O water dimer 7 A' 143 270 127 0.529
H2OH2O water dimer 10 A" 523 776 253 0.674
H2OH2O water dimer 11 A" 108 181 73 0.598
H2OH2O water dimer 12 A" 88 -129 -217 -0.682
H2POH Phosphinous acid 9 A" 375 247 -128 1.520
Mg2 Magnesium diatomic 1 Σg 51 119 68 0.430
ClOF3 Chlorine trifluoride oxide 5 A' 319 258 -61 1.238
ClOF3 Chlorine trifluoride oxide 6 A' 224 180 -44 1.242
ClOF3 Chlorine trifluoride oxide 9 A" 412 335 -77 1.228
ZnCH3 Zinc monomethyl 6 E 315 589 274 0.534
ClONO chlorine nitrite 4 A' 406 330 -76 1.228
ClONO chlorine nitrite 5 A' 270 162 -108 1.665
CH3BO Borane, methyloxo- 7 E 897 1364 467 0.657
HSO3 HOSO2 3 A 1296 1049 -247 1.236