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 ...

In this work we use density functional theory based on the ultra-soft pseudo-potential to calculate thestructural, mechanical and thermal properties of narrow single walled BN, AlN and GaN nanotubes.The electron-electron interactions were expressed within the local density approximation (LDA). Wehave also obtained the Phonon dispersion and elastic constants of these nanotubes using the densityf...

Density scaling has a rich history in density functional theory, providing exact conditions for use in the construction of ever more accurate approximations to the unknown exchange-correlation functional. We define a conjugate potential scaling for each density scaling. This provides exact relations on various important density functionals, in particular, relating functionals evaluated on exact...

theoretical study of the electronic structure, and nonlinear optical properties (nlo) analysis of 12-crown-4were done using density functional theory (dft) evaluations at the b3lyp/6-311g (d,p) level of theory. the optimized structure is nonlinear compound as indicated from the dihedral angles were presented. the calculated ehomo and elumo energies of 12-crown-4 (12cn4) can be used to explain t...

A density functional study of the structure of a layer formed by chain molecules pinned to a solid surface is presented. The chains are modeled as freely joined spheres. Segments and all components interact via LennardJones (12–6) potential. The interactions of fluid molecules with the wall are described by the Lennard-Jones (9–3) potential. We analyze how different parameters of the model affe...

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 research, the complexation of a new recently synthesized phenothiazine with 10 different metals was evaluated by Density functional theory. At the first step, the structures of 6,15-diazabenzo[a][1,4]benzothiazino[3,2-c]phenothiazine, cations and their complexes with the mentioned material were optimized geometrically. Then, IR calculations were performed on them to obtain the values of...