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/6-31G**
Calculated values were scaled by 0.9813.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 182 69 0.620
CH3COOH Acetic acid 18 A" 93 71 -22 1.308
CH3OH Methyl alcohol 12 A" 200 339 139 0.590
C2H6O2S Dimethyl sulfone 13 A2 326 264 -62 1.235
CH3CCl3 Ethane, 1,1,1-trichloro- 6 A2 214 312 98 0.686
C2H4+ Ethylene cation 4 Au 84 -821 -905 -0.102
CH3COCl Acetyl Chloride 15 A" 166 131 -35 1.269
CBr2F2 Methane, dibromodifluoro- 3 A1 140 329 189 0.425
C2F6 hexafluoroethane 4 A1u 68 29 -39 2.327
C3F8 perfluoropropane 13 A2 276 199 -77 1.384
CHOCH(CH3)CH3 Propanal, 2-methyl- 33 A" 75 60 -15 1.256
CF2CCl2 difluorodichloroethylene 7 B1 1327 568 -759 2.335
CF2CCl2 difluorodichloroethylene 8 B1 989 312 -677 3.174
CF2CCl2 difluorodichloroethylene 11 B2 564 445 -119 1.267
CF2CCl2 difluorodichloroethylene 12 B2 323 173 -150 1.870
C3H6O 2-Propen-1-ol 22 A 377 304 -73 1.241
C3H6O 2-Propen-1-ol 24 A 188 119 -69 1.586
CH3OCHO methyl formate 18 A" 130 88 -42 1.471
C5H8 Cyclopentene 18 A' 254 165 -89 1.542
C4H4N2 Pyridazine 13 A2 421 336 -85 1.251
C2H2N4 sym-tetrazine 5 Au 335 258 -77 1.298
C2H2N4 sym-tetrazine 18 B3u 254 -4 -258 -60.003
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 506 155 0.694
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 332 -877 3.644
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 406 -127 1.314
C4H6O2 2,3-Butanedione 21 Bg 240 47 -193 5.073
C4H6O2 2,3-Butanedione 16 Au 48 -34 -82 -1.421
C4H6O2 2,3-Butanedione 13 Au 1111 874 -237 1.272
C6F6 hexafluorobenzene 20 E2u 175 132 -43 1.326
C6F6 hexafluorobenzene 8 B2g 243 178 -65 1.369
C6F6 hexafluorobenzene 7 B2g 715 490 -225 1.461
C2H3NO3 Oxamic acid 3 A' 2600 3424 824 0.759
C2H3NO3 Oxamic acid 15 A' 328 257 -71 1.279
C2H3NO3 Oxamic acid 16 A" 984 787 -197 1.250
C2H3NO3 Oxamic acid 21 A" 162 87 -75 1.868
C3H6O Oxetane 12 A2 986 800 -186 1.233
C5H12 Propane, 2,2-dimethyl- 12 T1 203 323 120 0.629
C3H6O Oxetane 18 B1 90 -63 -153 -1.431
C3O2 Carbon suboxide 7 Πu 61 139 78 0.437
HCNO fulminic acid 5 Π 224 42 -182 5.305
C5H8 1,4-Pentadiene 16 A 137 284 147 0.483
CH3SCH2CH3 Ethane, (methylthio)- 18 A' 227 180 -47 1.259
CH3SSCH3 Disulfide, dimethyl 13 A 117 73 -44 1.596
C2F2 difluoroacetylene 4 Πg 270 166 -104 1.627
C6H8 (E)-hexa-1,3,5-triene 36 Bu 170 136 -34 1.252
CuO Copper Monoxide 1 Σ 640 931 291 0.687
SiF2+ Silicon difluoride cation 2 A1 350 272 -78 1.286
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 216 72 0.666
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 340 -116 1.340
CH3OO methylperoxy radical 12 A" 170 126 -44 1.351
CH3 Methyl radical 2 A2" 606 482 -124 1.257
CH2OH Hydroxymethyl radical 9 A 234 427 193 0.548
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 875 -261 1.298
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 166 -98 1.594
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 109 -249 3.288
CHCl2 dichloromethyl radical 4 A' 190 280 90 0.679
C4H6 Methylenecyclopropane 17 B1 360 280 -80 1.285
C2Cl2 dichloroacetylene 4 Πg 333 245 -88 1.358
HClO4 perchloric acid 12 A" 191 127 -64 1.510
MgF2 Magnesium fluoride 3 Πu 165 134 -31 1.232
SF4 Sulfur tetrafluoride 4 A1 228 177 -51 1.290
BrF5 bromine pentafluoride 6 B2 281 198 -83 1.422
CaF2 Calcium difluoride 2 A1 120 19 -101 6.250
PCl5 Phosphorus pentachloride 2 A1' 370 279 -91 1.325
N2O3 Dinitrogen trioxide 9 A" 63 151 88 0.417
SF5 Sulfur pentafluoride 9 E 387 307 -80 1.260
C3 carbon trimer 3 Πu 63 137 74 0.461
SiH- silicon monohydride anion 1 Σ 2175 1752 -423 1.241
SF5Cl sulfur chloropentafluoride 5 B1 625 444 -181 1.407
SF5Cl sulfur chloropentafluoride 7 B2 505 297 -208 1.698
SF5Cl sulfur chloropentafluoride 11 E 397 233 -164 1.706
H3O+ hydronium cation 2 A1 954 693 -262 1.378
ZnH2 Zinc hydride 3 Πu 633 470 -163 1.347
C2H4O4 Formic acid dimer 2 Ag 2949 1897 -1052 1.555
C2H4O4 Formic acid dimer 13 Au 1050 83 -967 12.656
C2H4O4 Formic acid dimer 18 Bu 2939 2067 -872 1.422
C2H4O4 Formic acid dimer 24 Bu 268 490 222 0.547
ClOO chloroperoxy radical 3 A' 201 316 115 0.637
B2H6 Diborane 14 B2u 368 262 -106 1.403
H2OH2O water dimer 6 A' 311 585 274 0.531
H2OH2O water dimer 7 A' 143 327 184 0.437
H2OH2O water dimer 10 A" 523 785 262 0.666
H2OH2O water dimer 11 A" 108 205 97 0.527
H2OH2O water dimer 12 A" 88 -206 -294 -0.428
H2POH Phosphinous acid 9 A" 375 244 -132 1.540
Mg2 Magnesium diatomic 1 Σg 51 119 68 0.430
ClOF3 Chlorine trifluoride oxide 6 A' 224 181 -43 1.239
ZnCH3 Zinc monomethyl 6 E 315 594 279 0.531
ClONO chlorine nitrite 5 A' 270 185 -85 1.462
CH3BO Borane, methyloxo- 7 E 897 1372 476 0.653
HSO3 HOSO2 3 A 1296 1047 -249 1.237