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(T)/cc-pVDZ
Calculated values were scaled by 0.9531.

Species Name mode Symmetry Experiment Theory difference ratio
CH3OH Methyl alcohol 12 A" 200 332 132 0.603
C2H4+ Ethylene cation 4 Au 84 -270 -354 -0.312
HCN+ hydrogen cyanide cation 3 Π 760 2061 1301 0.369
CHONH2 formamide 12 A" 289 -274 -563 -1.053
C10H8 naphthalene 27 B2g 770 540 -230 1.426
C3H6O 2-Propen-1-ol 24 A 188 108 -80 1.747
F2CCCF2 tetrafluoroallene 5 B2 2052 693 -1359 2.963
F2CCCF2 tetrafluoroallene 6 B2 1030 552 -478 1.867
F2CCCF2 tetrafluoroallene 7 B2 581 371 -210 1.564
C3H6O Oxetane 18 B1 90 -35 -125 -2.572
HCNO fulminic acid 5 Π 224 -340 -564 -0.658
C6H6 Benzvalene 10 A1 996 722 -274 1.380
H2CS- thioformaldehyde anion 4 B1 450 -214 -664 -2.106
SiF2+ Silicon difluoride cation 2 A1 350 261 -89 1.341
C5H8 1,3-Pentadiene, (Z)- 22 A' 144 208 64 0.691
C5H8 1,3-Pentadiene, (Z)- 31 A" 456 325 -131 1.401
C5H8 1,3-Pentadiene, (Z)- 32 A" 171 119 -52 1.441
C2H Ethynyl radical 3 Π 372 244 -128 1.525
CH3 Methyl radical 2 A2" 606 383 -223 1.582
CH2OH Hydroxymethyl radical 9 A 234 436 202 0.537
HCCN cyanomethylene 5 Π 129 -431 -560 -0.299
CHCl2 dichloromethyl radical 4 A' 190 288 98 0.660
HClO4 perchloric acid 12 A" 191 137 -54 1.396
OClO- Chlorine dioxide anion 1 A1 790 627 -163 1.260
OClO- Chlorine dioxide anion 2 A1 418 288 -130 1.452
Li2O dilithium oxide 3 Πu 112 87 -24 1.279
FO Oxygen monofluoride 1 Σ 1053 801 -252 1.314
TiO Titanium monoxide 1 Σ 1009 2212 1203 0.456
KrF2 Krypton difluoride 1 Σg 449 229 -220 1.958
SiH- silicon monohydride anion 1 Σ 2175 1709 -466 1.272
BrF+ bromine fluoride cation 1 Σ 750 590 -160 1.271
HOClO Chlorous acid 4 A 592 416 -175 1.422
OPCl Phosphorus oxychloride 2 A' 308 464 156 0.664
OPCl Phosphorus oxychloride 3 A' 492 282 -210 1.744
H2OH2O water dimer 11 A" 108 168 60 0.643
H2POH Phosphinous acid 9 A" 375 231 -144 1.626
Mg2 Magnesium diatomic 1 Σg 51 16 -35 3.150