return to home page Computational Chemistry Comparison and Benchmark DataBase Release 18 (October 2016) Standard Reference Database 101 National Institute of Standards and Technology
You are here: Calculated > Vibrations > Bad Calculations > Bad vib. Calc. vs exp. OR Resources > Bad Calculations > Vibrations > Bad vib. Calc. vs exp.

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 B1B95/6-31G*
Calculated values were scaled by 0.9493.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 170 57 0.663
CH3CONH2 Acetamide 20 A 259 165 -94 1.566
CH3OH Methyl alcohol 12 A" 200 330 130 0.607
C2H4+ Ethylene cation 4 Au 84 -447 -531 -0.188
CHONH2 formamide 12 A" 289 135 -154 2.136
CH3COCl Acetyl Chloride 15 A" 166 129 -37 1.282
CBr2F2 Methane, dibromodifluoro- 3 A1 140 323 183 0.433
C2F6 hexafluoroethane 4 A1u 68 41 -27 1.648
C3F8 perfluoropropane 13 A2 276 195 -81 1.412
CH3COOCH3 methyl acetate 26 A" 136 80 -56 1.704
CH3COOCH3 methyl acetate 27 A" 110 49 -61 2.254
CF2CCl2 difluorodichloroethylene 7 B1 1327 577 -750 2.299
CF2CCl2 difluorodichloroethylene 8 B1 989 318 -671 3.115
CF2CCl2 difluorodichloroethylene 11 B2 564 441 -123 1.279
CF2CCl2 difluorodichloroethylene 12 B2 323 170 -153 1.895
C3H6O 2-Propen-1-ol 24 A 188 112 -76 1.685
CH3CH2CHO Propanal 24 A" 135 104 -31 1.293
C5H8 Cyclopentene 18 A' 254 149 -105 1.704
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 516 165 0.680
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 335 -874 3.608
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 398 -135 1.339
C6F6 hexafluorobenzene 7 B2g 715 497 -218 1.440
C6F6 hexafluorobenzene 8 B2g 243 175 -68 1.387
C6F6 hexafluorobenzene 20 E2u 175 130 -45 1.351
C4H6O2 2,3-Butanedione 21 Bg 240 102 -138 2.353
C6H4 Benzyne 24 B2 472 370 -102 1.276
C5H12 Propane, 2,2-dimethyl- 12 T1 203 295 92 0.688
C2H3NO3 Oxamic acid 3 A' 2600 3450 850 0.754
C2H3NO3 Oxamic acid 15 A' 328 252 -76 1.303
C2H3NO3 Oxamic acid 21 A" 162 70 -92 2.329
C3H6O Oxetane 18 B1 90 10 -80 9.216
C3O2 Carbon suboxide 7 Πu 61 112 51 0.547
C5H8 1,4-Pentadiene 16 A 137 282 145 0.486
SiF2+ Silicon difluoride cation 2 A1 350 276 -74 1.269
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 210 66 0.684
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 341 -115 1.337
CH3 Methyl radical 2 A2" 606 401 -206 1.513
CH2OH Hydroxymethyl radical 9 A 234 439 205 0.533
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 863 -273 1.316
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 145 -119 1.824
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 98 -260 3.672
CHCl2 dichloromethyl radical 4 A' 190 296 106 0.643
C4H6 Methylenecyclopropane 17 B1 360 281 -79 1.282
BrF5 bromine pentafluoride 6 B2 281 210 -71 1.339
ZnCN Zinc monocyanide 3 Π 212 68 -144 3.122
PCl5 Phosphorus pentachloride 2 A1' 370 273 -97 1.355
N2O3 Dinitrogen trioxide 9 A" 63 145 82 0.436
C3 carbon trimer 3 Πu 63 138 75 0.458
SF5Cl sulfur chloropentafluoride 5 B1 625 447 -178 1.397
SF5Cl sulfur chloropentafluoride 7 B2 505 306 -199 1.648
SF5Cl sulfur chloropentafluoride 11 E 397 239 -158 1.658
ZnH2 Zinc hydride 3 Πu 633 491 -142 1.288
C2H4O4 Formic acid dimer 13 Au 1050 69 -981 15.183
H2OH2O water dimer 7 A' 143 211 68 0.679
H2OH2O water dimer 11 A" 108 164 56 0.658
H2OH2O water dimer 12 A" 88 69 -19 1.274
H2POH Phosphinous acid 9 A" 375 254 -121 1.478
CH3BO Borane, methyloxo- 7 E 897 1413 516 0.635
ZnCH3 Zinc monomethyl 6 E 315 585 270 0.538