We report how closely the Kohn-Sham highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) eigenvalues of 11 density functional theory (DFT) functionals, respectively, correspond to the negative ionization potentials (-IPs) and electron affinities (EAs) of a test set of molecules. We also report how accurately the HOMO-LUMO gaps of these methods predict the low...

using the computational methods, the interaction effect of tyrosine amino acid on graphene wasinvestigated. for this purpose, the density functional theory (dft) in the ground state of 6-31gwas used, and the interaction effects of tyrosine on graphene was investigated through attachmentto three different base positions. different parameters such as energy levels, the amount ofchemical shift in ...

in this study the hardness swct was calculated with b3lyp,hf method and 3-21g,6-31g,6-311g basis set .then it was investigated with the best method(b3lyp) and basis set(6-31g) to study the adsorption effects co2 on the hardness of swcnt with gap homo-lumo in two shape: horizontal, vertical and top-center-bridge and we also provide the effects of co2 adsorption on the electronic properties(dos) ...

Representative atomic and molecular systems, including various inorganic and organic molecules with covalent and ionic bonds, have been studied by using density functional theory. The calculations were done with the commonly used exchange-correlation functional B3LYP followed by a comprehensive analysis of the calculated highest-occupied and lowest-unoccupied Kohn-Sham orbital (HOMO and LUMO) e...

the density functional theory (dft) and the natural bond orbital (nbo) calculations basedmethod b3lyp/6-31g* were carried out to study the interaction of carbon nanotube (8,0) withnitrobenzene in two situations perpendicular and parallel. formation energies of compounds,charges, the highest occupied molecular orbital (homo) and the lowest unoccupied molecular'orbital (lumo) and the homo-lumo ba...

A series of substituted 2-(2-hydroxyphenylimino) phenolic (salen) derivatives (1-4) have been synthesized and their structures of obtained compound were characterized by analytical, FT-IR, UV-Vis and C{H}-NMR experimentally. The geometry structure optimization, frequencies (IR), NMR, electronic character, frontier molecular orbital (HOMO-LUMO) and first static hyperpolarizability (βtot) studies...

in this work, we have studied binding of clonidine drug (c9h9cl2n3) with zigzag single walled carbonnanotubes (swcnt) (5, 0) by theoretical methods of theory using gaussian 09 software package.binding energies, nmr parameters and homo- lumo gap energy were calculated. results frombinding energies indicate that it is possible thermodynamically to bind clonidine drug to swcnt.the calculated nmr p...

Differences between exchange methods in exchange-only Kohn-Sham theory are highlighted by calculations of diatomic molecule total energies, uncoupled isotropic NMR shieldings, and HOMO-LUMO eigenvalue differences. Optimised effective potential (OEP) and Wu-Yang (WY) results are very similar. Localised Hartree-Fock (LHF) and Krieger-Li-Iafrate (KLI) results are close to one another, but are diff...