the effect of impurities on quantum chemical parameters of single-walled nanotubes (swnts) was studied using density functional theory (dft). the density of states (dos), fermi energy and thermodynamic energies of (5,5) carbon nanotubes were calculated in the presence of nitrogen impurity. it was found that this nanotube remains metallic after being doped with one nitrogen atom. the partial den...

 The two-dimensional structure of graphene, consisting of an isotropic hexagonal lattice of carbon atoms, shows fascinating electronic properties, such as a gapless energy band and Dirac fermion behavior of electrons at fermi surface. Anisotropy can be induced in this structure by electrochemical pressure. In this article, by using tight-binding method, we review anisotropy effects in the elect...

In this study the chemical properties of B6C4Si and C16 Clusters connected vitamin C have been investigated using density functional theory (DFT). NMR parameters and HOMO- LUMO Gap energy are calculated by using density functional method (B3LYP) with 6-311G* basis set. Calculations show that HOMO- LUMO Gap energy of vitamin C decreases after connecting to B6C4Si or C16 cluster decreasing of HOM...

the monitoring and controlling of environmental pollutions are very important in biological and industrial processes, and a great interest is growing with the development of suitable gas–sensitive materials and hazardous chemical removal devices. in this work, the highly parameterized, empirical exchange–correlation functional m06–2x were employed to investigate the electronic sensitivity of pe...

The structure and the electronic properties of single-walled zigzag BN and B3C2N3 nanotubes (n, 0; n=4–10) were investigated using first-principles calculations based on a density functional theory. A plane–wave basis set with periodic boundary conditions in conjunction with Vanderbilt ultrasoft pseudo-potential was employed. The energy gap of ZB3C<su...

The structure and the electronic properties of single-walled zigzag BN and B3C2N3 nanotubes (n, 0; n=4–10) were investigated using first-principles calculations based on a density functional theory. A plane–wave basis set with periodic boundary conditions in conjunction with Vanderbilt ultrasoft pseudo-potential was employed. The energy gap of ZB3C<su...

abstract: electrical sensitivity of a beryllium oxide nanotube (beont) was examined toward (c5h5n) molecule by using density functional theory (dft) calculations at the b3lyp/6-31(d) level, and it was found that the adsorption energy (ead) of pyridine on the pristine nanotubes is   a bout -73.29kcal/mol. but when nanotubes has been doped with s and p atomes , the adsorption energy changed . cal...