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 ...

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...

the electronic and structural properties of pristine and carbon doped (c-doped) boron nitride nano-ribbons(bnnrs) have been studied employing density functional theory (dft) calculations. total energies, gapenergies, dipole moments, and quadrupole coupling constants (qcc) have been calculated in the optimizedstructures of the investigated bnnrs. the results indicated that the stability and gap ...

density functional theory (dft) calculations were performed to investigate the effects of a carbon nanotube (cnt) on the properties of the fluorouracil (f-uracil) anticancer drug. to achieve the purpose, a molecular model including both of f-uracil and cnt molecules was created to represent the cnt@f-uracil compound. the optimized parameters indicated that the new compound could show new proper...

in this study, the structures, the ir spectroscopy, and the electronic properties of auncum (n+m≤5) bimetallic clusters were studied and compared with those of pure gold and copper clusters using the generalized gradient approximation (gga) and exchange correlation density functional theory (dft). the study of an o2-auncum system is important to identify the promotion effects of each of the two...

the density and polarization profiles of the dipolar hard ellipsoids confined between hard walls are studied using the density functional theory (dft). the hyper-netted chain (hnc) approximation is used to write excess grand potential of the system with respect to the bulk value. the number density is expanded up to zero and first order in polarization to find the results. for the zero order in...

density functional theory (dft) based calculations have been performed to examine the relaxations of tautomers of 4–hydroxy–6–methylpyridin–2(1h)–one (mpo), as a representative of pyridinone derivatives, at the fullerene (c60) surfaces. optimized molecular properties including energies, dipole moments and atomic scale quadrupole coupling constants (cq) have been evaluated to investigate the str...

the adsorption of a number of amino acids on a defected single-walled carbon nanotube (swcnt) isinvestigated by using the density-functional theory (dft) calculations. the adsorption energies andequilibrium distances are calculated for various configurations such as amino acid attaching to defectsites heptagon, pentagon and hexagon in defective tube and also for several molecular orientationswi...