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 B3PW91/6-31G*
Calculated values were scaled by 0.9567.

Species Name mode Symmetry Experiment Theory difference ratio
C3H4O2 β–Propiolactone 21 A" 113 176 63 0.644
CH3CONH2 Acetamide 20 A 259 122 -136 2.116
CH3COOH Acetic acid 18 A" 93 74 -19 1.260
CH3OH Methyl alcohol 12 A" 200 331 131 0.603
CH3COCH3 Acetone 12 A2 77 12 -65 6.275
C2H6O2S Dimethyl sulfone 20 B1 262 209 -53 1.256
C2H4+ Ethylene cation 4 Au 84 -421 -505 -0.200
CHONH2 formamide 12 A" 289 144 -144 2.000
CH3COCl Acetyl Chloride 15 A" 166 130 -36 1.279
CBr2F2 Methane, dibromodifluoro- 3 A1 140 320 180 0.438
C2F6 hexafluoroethane 4 A1u 68 48 -20 1.408
C3F8 perfluoropropane 13 A2 276 208 -68 1.328
CH3COOCH3 methyl acetate 27 A" 110 45 -65 2.436
CF2CCl2 difluorodichloroethylene 7 B1 1327 572 -755 2.319
CF2CCl2 difluorodichloroethylene 8 B1 989 317 -672 3.120
CF2CCl2 difluorodichloroethylene 11 B2 564 440 -124 1.280
CF2CCl2 difluorodichloroethylene 12 B2 323 178 -145 1.816
C3H6O 2-Propen-1-ol 24 A 188 112 -76 1.678
C5H8 Cyclopentene 18 A' 254 137 -117 1.849
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 6 A2 351 510 159 0.688
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 336 -873 3.598
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 400 -133 1.331
C4H6O2 2,3-Butanedione 21 Bg 240 105 -135 2.284
C2H3NO3 Oxamic acid 3 A' 2600 3459 859 0.752
C2H3NO3 Oxamic acid 15 A' 328 256 -72 1.283
C2H3NO3 Oxamic acid 21 A" 162 66 -96 2.443
C3H6O Oxetane 18 B1 90 52 -38 1.731
C3O2 Carbon suboxide 7 Πu 61 117 56 0.521
C5H8 1,4-Pentadiene 16 A 137 285 148 0.481
CH3ONO Methyl nitrite 15 A" 186 122 -64 1.525
C2F2 difluoroacetylene 4 Πg 270 208 -62 1.298
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 207 63 0.695
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 343 -113 1.331
CH3 Methyl radical 2 A2" 606 438 -169 1.386
CH2OH Hydroxymethyl radical 9 A 234 427 193 0.548
C6H8 (Z)-hexa-1,3,5-triene 11 A1 1136 866 -270 1.312
C6H8 (Z)-hexa-1,3,5-triene 19 A2 264 147 -117 1.790
C6H8 (Z)-hexa-1,3,5-triene 24 B1 358 99 -259 3.619
CHCl2 dichloromethyl radical 4 A' 190 295 105 0.643
C4H6 Methylenecyclopropane 17 B1 360 281 -79 1.282
BrF5 bromine pentafluoride 6 B2 281 206 -75 1.361
ZnCN Zinc monocyanide 3 Π 212 56 -156 3.815
PCl5 Phosphorus pentachloride 2 A1' 370 266 -104 1.393
N2O3 Dinitrogen trioxide 9 A" 63 139 76 0.452
C3 carbon trimer 3 Πu 63 145 81 0.438
CaOH Calcium monohydroxide 2 Σ 353 599 246 0.589
CaOH Calcium monohydroxide 3 Π 609 338 -271 1.799
Cu2 Copper dimer 1 Σg 265 387 122 0.684
TiO2 Titanium dioxide 1 A1 959 341 -618 2.815
SF5Cl sulfur chloropentafluoride 5 B1 625 443 -182 1.409
SF5Cl sulfur chloropentafluoride 7 B2 505 299 -206 1.687
SF5Cl sulfur chloropentafluoride 11 E 397 235 -162 1.687
ZnH2 Zinc hydride 3 Πu 633 492 -141 1.286
C2H4O4 Formic acid dimer 13 Au 1050 72 -978 14.555
ClOO chloroperoxy radical 2 A' 414 325 -89 1.274
ClOO chloroperoxy radical 3 A' 201 116 -85 1.732
H2OH2O water dimer 7 A' 143 218 75 0.656
H2OH2O water dimer 8 A' 103 149 46 0.693
H2OH2O water dimer 11 A" 108 171 63 0.633
H2POH Phosphinous acid 9 A" 375 250 -125 1.501
Mg2 Magnesium diatomic 1 Σg 51 83 32 0.613
ZnCH3 Zinc monomethyl 6 E 315 596 281 0.529
CH3BO Borane, methyloxo- 7 E 897 1420 523 0.632