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 CCSD(T)=FULL/6-31G*
Calculated values were scaled by 0.9707.

Species Name mode Symmetry Experiment Theory difference ratio
CH3SeH Methane selenol 12 A" 145 211 66 0.688
CH3OH Methyl alcohol 12 A" 200 339 139 0.591
C6H6 Benzene 8 B2g 703 540 -163 1.302
C2H4+ Ethylene cation 4 Au 84 -286 -370 -0.294
C2H2 Acetylene 4 Πg 612 348 -264 1.760
CHONH2 formamide 12 A" 289 -191 -479 -1.514
CBr2F2 Methane, dibromodifluoro- 3 A1 140 327 187 0.429
CF2CCl2 difluorodichloroethylene 7 B1 1327 546 -781 2.428
CF2CCl2 difluorodichloroethylene 8 B1 989 317 -672 3.123
CF2CCl2 difluorodichloroethylene 11 B2 564 448 -116 1.260
CF2CCl2 difluorodichloroethylene 12 B2 323 184 -139 1.759
CHCCH2CH3 1-Butyne 22 A" 630 505 -125 1.248
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 8 B1 1209 329 -880 3.677
CFClCFCl cis-1,2-dichloro-1,2-difluoroethylene 12 B2 533 406 -127 1.312
C4H2 Diacetylene 7 Πg 482 276 -206 1.746
C4H2 Diacetylene 8 Πu 630 447 -183 1.410
C3H6O Oxetane 18 B1 90 -69 -159 -1.305
HCNO fulminic acid 5 Π 224 -226 -450 -0.991
HCCCl Chloroacetylene 5 Π 326 204 -122 1.595
GeO2 Germanium dioxide 3 Πu 196 120 -75 1.629
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 221 77 0.652
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 335 -121 1.362
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 115 -56 1.483
C2H Ethynyl radical 3 Π 372 297 -74 1.249
CH3 Methyl radical 2 A2" 606 421 -185 1.439
CH2OH Hydroxymethyl radical 8 A 482 719 237 0.671
CH2OH Hydroxymethyl radical 9 A 234 437 203 0.535
CHCl2 dichloromethyl radical 4 A' 190 302 112 0.628
N2O Nitrous oxide 3 Π 596 402 -194 1.482
NCl3 nitrogen trichloride 4 E 257 621 364 0.414
C3 carbon trimer 3 Πu 63 98 35 0.644
SiH- silicon monohydride anion 1 Σ 2175 1759 -416 1.236
SF5Cl sulfur chloropentafluoride 5 B1 625 459 -166 1.361
SF5Cl sulfur chloropentafluoride 7 B2 505 314 -191 1.611
SF5Cl sulfur chloropentafluoride 11 E 397 246 -151 1.615
Cl3- trichloride anion 2 Σu 327 264 -63 1.238
H2OH2O water dimer 11 A" 108 158 50 0.685
H2POH Phosphinous acid 9 A" 375 252 -124 1.491
Mg2 Magnesium diatomic 1 Σg 51 18 -33 2.883
CH3BO Borane, methyloxo- 7 E 897 1466 569 0.612