return to home page Computational Chemistry Comparison and Benchmark DataBase Release 19 (April 2018) 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 QCISD/cc-pVDZ
Calculated values were scaled by 0.9594.

Species Name mode Symmetry Experiment Theory difference ratio
CH3OH Methyl alcohol 12 A" 200 332 132 0.602
C2H4+ Ethylene cation 4 Au 84 -212 -297 -0.396
HCN+ hydrogen cyanide cation 3 Π 760 1104 344 0.689
CHONH2 formamide 12 A" 289 -261 -549 -1.108
C10H8 naphthalene 27 B2g 770 606 -164 1.270
C6H4O2 parabenzoquinone 30 B3u 109 86 -23 1.263
C3H6O 2-Propen-1-ol 24 A 188 107 -81 1.763
C5H8 Cyclopentene 18 A' 254 172 -82 1.475
NH2CN cyanamide 5 A' 408 725 317 0.562
C4H6O2 2,3-Butanedione 21 Bg 240 121 -119 1.984
C3H6O Oxetane 18 B1 90 28 -61 3.171
HCNO fulminic acid 5 Π 224 -194 -418 -1.153
CH3SSCH3 Disulfide, dimethyl 13 A 117 93 -24 1.259
C6H6 Benzvalene 10 A1 996 738 -258 1.350
H2CS- thioformaldehyde anion 4 B1 450 -201 -651 -2.244
NaOH sodium hydroxide 3 Π 300 226 -74 1.326
SiF2+ Silicon difluoride cation 2 A1 350 266 -84 1.315
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 211 67 0.682
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 337 -119 1.353
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 118 -53 1.452
CH3 Methyl radical 2 A2" 606 387 -219 1.566
CH2OH Hydroxymethyl radical 9 A 234 432 198 0.541
HCCN cyanomethylene 5 Π 129 -429 -558 -0.300
CHCl2 dichloromethyl radical 4 A' 190 293 103 0.649
HClO4 perchloric acid 12 A" 191 146 -45 1.310
OClO- Chlorine dioxide anion 2 A1 418 303 -115 1.379
N2O3 Dinitrogen trioxide 9 A" 63 144 81 0.437
Li2O dilithium oxide 3 Πu 112 86 -26 1.303
TiO Titanium monoxide 1 Σ 1009 4237 3228 0.238
MgOH magnesium hydroxide 3 Π 188 101 -87 1.870
SiH- silicon monohydride anion 1 Σ 2175 1734 -441 1.254
Cl3- trichloride anion 2 Σu 327 246 -81 1.329
OPCl Phosphorus oxychloride 2 A' 308 475 167 0.649
OPCl Phosphorus oxychloride 3 A' 492 291 -201 1.689
H2POH Phosphinous acid 9 A" 375 234 -141 1.604
Mg2 Magnesium diatomic 1 Σg 51 14 -37 3.656
Al2 Aluminum diatomic 1 Σg 286 429 143 0.666