|Molecular Structure Calculations|
The calculations in this database include bond lengths, angles, atomic charges, the dipole moment, bond orders, and molecular orbital energies. The best Lewis structure that fits the molecular orbitals is also calculated, so you can directly compare with your predictions. This best Lewis structure is presented with formal electron pair localized bonds and the hybridization of the atomic orbitals used to form these localized bonds. The Chime plugin is needed to see the 3-D structure of the molecules in these pages. See the link at the bottom of the page for the Chime plugin.
Molecular orbital theory is based on approximations also. These calculations are done with some of the best available calculation methods (DFT for geometry and molecular orbital energies and ab initio for properties). We use Alain St-Amant's DeFT program (University of Ottawa).
The Molecular Structure Input Form, see below, will allow you to do calculations for molecules not in the database. These calculations take time; 1-2 hours in some cases.
You can use the Formula Search page or browse the links below. As of 07/12/05 there are 1056
structures in the database.
A Best Lewis Structure and Donor Acceptor Interactions Tutorial is available to help you interpret those output sections. These Lewis structure calculations are done using NBO Analysis.
Answer some Study Questions to help your understanding of some interesting chemistry.
Many More Diatomic molecules and ions
BF3 BF32- BF4+ BF2O- BCl3 BH3NH3 BH3CO BH3PH3 BO2NO
C3 C5 H2O H3O+ H4O+ O3 O4 CO2 OCS cyclic CO2 CO2- HCO+ HOC+
N3 radical N3 quartet HN3 N3- NCO HNCNH CNNO
NO2 NO2+ NO2- HOON NOO- NO2- triplet NO22+ NO3- NO3-triplet NO2O-
N2O cyclic N2O cyclic N2O2 N2O4 NO2NO
ONOOH N2H2 N2H2 triplet H2NN H2NN triplet NH2F NHF2 NF3 NF4- N2F2 N2F4 BNHF
HNCl+ NH2Cl N3Cl NCl2 NCl3 NOCl ONCl NClO ClNO2 ClNOO t-ClONO OCl2
OF2 FOO FOOF FNO2 FOON F3- Cl3- Cl3F ClF2+
AlH3 AlF3 AlCl3 Al2Cl6
SiH4 SiH3SiH3 SiO2
P2 PCl3 SO2 SO3 SO3- SOCl2 SO2Cl2 ClO2 ClOO ClO2+ ClO2- ClOO-
FClO FClO2 K2O
Many More Binary Hydrides and their Anions, Cations, and Radicals
Many More Triatomic molecules and their Anions, Cations, and Radicals
Many More Period 3 Compounds, Al, Si, P, S, and Cl
Many More Period 4 Compounds, Ga, Ge, As, Se, and Br
Hydroxyl Compounds, Donor-Acceptor Oxides, Oxyacids, and Anions
Many More Formally Double Bonded Hydroxyl Compounds, Donor-Acceptor Oxides, and Oxyacids (e.g.Carbonic and Nitric acid)
Carbon Compounds, Organics, and Organic Reagents
Many More Organic Radical Cations, Neutral Radicals, Cations, and Anions
This work was supported by an Academic Research Infrastructure Grant from the National Science Foundation, no. 9512457.
Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.