density functional theory (dft) calculations were performed to investigate the properties of planar, tubular and conical forms of silicon nanostructures. the evaluated parameters including averaged bond lengths, binding energies, gap energies and dipole moments were then evaluated for the optimized models of study. the results indicated that the bond lengths between silicon atoms are different ...

we have investigated the electronic structure and thermodynamic properties of supercell of the
-al2o3 by first-principles calculation in framework of density functional theory (dft) and full potential linearized augmented plane wave (fp-lapw) with generalized gradient approximation (gga) and by quasi-harmonic debye model. our calculated value for direct band gap of α-al2o3 is 7.2 ev which is v...

In this work, we report results of calculations based on the density functional theory of different species metal-ozone, containing mercury, silver and gold. The chosen species range from small molecules and large transition-metal containing ozone with mercury, silver and gold complexes. A comparative analysis of the description of the metal-oxygen bond obtained by different methodologies is pr...

Tetrazole-containing compounds have been the subject of much recent research because of theirpotential as high energy density materials (HEDMs). In this work, theoretical studies on the 1Htetrazolylderivatives of tetrahedrane were done at the density functional theory (DFT) method withthe 6-31G(d) basis set without any symmetrical restrictions in order to find the structural andenergetically pr...

One main group of organic chemistry is related to the aromatic compounds. In the present work, we replaced the CH group of benzene by silicon and nitrogen analogues. Then, Density functional theory (DFT) calculations were carried out for six-membered heterocyclic Si-N aromatic rings. Full geometry optimizations were performed in gas-phase, and at B3LYP level using 6-311++G(d,p) and CBSB7 basis ...

The electronic structure and properties of the osmaabenzenes and para substituted osmabenzenes have been explored using the hybrid density functional mpw1pw91 theory. Systematic studies on the substituent effect in para substituted osmabenzenes complexes have been studied. The following substituents were taken into consideration: H, F, CH3,OH, NH2,CN, NO<...

The electronic and structural properties of single wall carbon nanotubes (SWCNTs) interacted with 4-amino phenyl-azobenzene were theoretically investigated by using the hybrid DFT (hybrid-density functional theory) calculations. The amount of thermodynamic parameters of this reaction in the gas and aqueous phase suggesting thermodynamic favourability for adsorption of 4-amino phenyl-azobenzene ...

The electronic structure, Non-Linear Optical (NLO) properties and Natural Bonding Orbital (NBO) analysis of 1,4-dioxane were investigated using the theoretical study of Density Functional Theory (DFT) calculations at the B3LYP/6-311G (d,p) level of theory. The optimized structure is nonlinear as indicated from the dihedral angles.  Natural bonding orbital analysis has been analyzed in terms...

We have investigated photosensitizing properties for porphrazine and eleven of its related derivatives based on time-dependent density functional theory (TD-DFT) calculations. The modles have been divided into two categories based on the existence of CN functional group in one category but not in the other one. The other functional groups include H, CH3, F, CF3, C6H5, and C6F5 counterparts. The...