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...

We studied the UV-vis absorption and fluorescence in solution/solid states of [n]cycloparaphenylene ([n]CPP: n = 9, 12, 14, 15, and 16), and conducted theoretical studies to better understand the experimental results. The representative experimental findings include (i) the most intense absorption maxima (λ(abs1)) display remarkably close values (338-339 nm), (ii) the longest-wavelength absorpt...

The nonlinear optical properties of new tetrathiafulvalenes and 1,3-dithioles have been studied using first principle methods. The higher hyperpolarizabilities of the extended 1,3-dithioles compared to Tetrathiafulvalene analogs are explained on the basis of the less localized HOMO of the former giving rise to higher transition dipole moments and a more pronounced decrease of the HOMO-LUMO gap ...

The influence of the insertion/addition of a benzene ring to the natural nucleic acid bases on the local aromaticity of the so-called size-expanded (xN, with N being adenine, guanine, cytosine, and thymine) bases is examined. To this end, the local aromaticity of the six- and five-membered rings in both the natural bases and their benzoderivatives is determined using HOMA, NICS, aromatic fluctu...

In this paper and in order to guide the synthesis of novels materials with low band gaps, Theoretical study by using DFT method on six conjugated compound containing based on thiadiazolothienopyazine is reported. Different electron side groups were introduced to investigate their effects on the electronic structure. The theoretical knowledge of the HOMO and LUMO energy levels of the components ...

The extended SSH model and Bogoliubov-de Gennes(BdeG) formalism are applied to investigate the electronic properties and stable lattice configurations of C36. We focus the problem on the molecule’s unusual D6h symmetry. The electronic part of the Hamiltonian without Coulomb interaction is solved analytically. We find that the gap between HOMO and LUMO is small due to the long distance hopping b...

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...

Using an ab initio molecular-dynamics scheme ~the ‘‘fireball’’ scheme!, we determined the equilibrium structure of intermediate-size SinGem (n1m571) nanoclusters with and without hydrogen passivation on the surface. Due to the strong surface distortion, defect states are found to permeate the energy gap of SinGem clusters. However, the defect states are removed by adding H atoms on the surface ...