The antiaromaticity of a series of dianions of p-substituted benzylidene dibenzo[a,d]cycloheptenes was examined through calculated measures of antiaromaticity. The nucleus-independent chemical shifts (NICS) and magnetic susceptibility exaltation both showed substantial antiaromatic character in the benzannulated tropylium anion. When the antiaromaticity was normalized for the area of the ring, ...

Clusters play important role for understanding and transferring microscopic to macroscopic properties.Geometric and electron properties of Small nickel clusters up to the tetramer has been investigated by Density Functional Theory (DFT). Raising the number of nickel clusters atoms were indicated decreasing the average equilibrium (Ni-Ni) distance of atoms and also the binding energy of per atom...

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...

in this work, the effects of as-doped on the adsorption of oxygen gas on the outer and inner surface ofboron nitride nanotube (bnnts) is investigated. the structural parameters, quantum properties involving:bond length, bond angle, homo-lumo orbital, gapenergy, electron affinity, electronegativity, chemicalpotential, global hardness, global softness and nmr parameters of bnnts are calculated at...

Benzyl chloride and tin powder were used to prepare dibenzyltin dichloride according to a literatureprocedure. In this study, IR spectroscopy, HOMO-LUMO energy gap, NBO analysis, polarizability,some geometrical parameters, natural charge and electrical potential of atoms, global hardness,electronic chemical potential, global electrophilicity index, and molar volume of dibenzyltindichloride were...

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...

Quantum mechanical calculations are performed on 116 conformers of the protein ubiquitin (Lange et al., Science 2008, 320, 1471–1475). The results indicate that the heat of formation (HOF), dipole moment, energy of the frontier orbitals HOMO and LUMO, and HOMO-LUMO gap fluctuate within their corresponding ranges. This study thus provides a link between the conformational dynamics of a protein a...

In this paper theoretical study by using DFT method on three conjugated compound based on 2-styryl-5-phenylazo-pyrrole is reported. These dyes contain one carboxy, two carboxy and one sulfonic acid anchoring groups, the aim is to investigate their effects on the electronic structure. The theoretical knowledge of the HOMO and LUMO energy levels of the components is cannot be ignored in investiga...

in the present work, the structural and electronic properties, and conductivity of (5,5) and (6,6) single walled carbon nanotubes in the ground state have done by using the hartree-fock and density functional theory dft-b3lyp/6-31g* level. delocalization of charge density between the bonding or lone pair and antibonding orbitals calculated by nbo (natural bond orbital) analysis. these methods a...

The stability,optimized structure,binding energy,dipole moment and electronic gap of adamantane, C10H16,incorporating cage-centered small atoms and ions (X@cage, where X = Li, Be, Na, Mg, He, and Ne) have been studied at the B3LYP hybrid level of theory. A wide variety of atoms and ions can be encapsulated by adamantane. The complexes are more stable for smaller and more highly charged metallic...