magnesium oxide nanotubes of finite length are investigated by the density functional theory (dft) at the b3lyp/6-31g (d) level. the (6, 0) zigzag and (4, 4) armchair of mgo nanotubes were considered and nuclear magnetic resonance properties including isotropic and anisotropic chemical shielding parameters (csi and csa) were calculated for 25mg and 17o atoms of the optimized structures for the ...

Esterification of oxidized carbon nanotubes (CNTs) can open a new route for the separation of zigzag and armchair nanotubes. We studied theoretically (by using hybrid DFT within the ONIOM embedding protocol) the reactions of monocarboxy-substituted oxidized tips of zigzag and armchair single-walled CNTs (SWCNTs) with methanol. According to the calculated values of activation energy, Gibbs free-...

geometrical structure, nuclear magnetic resonance (n1,1it) chemical shielding tensors, and chemical shiftsof silicon and carbon nucler are investigated for twn infinite size zigzag and armchair single-walled siliconcarbide nanotabes (sicnts). geometrical structures of sients, sit bonds and bond angles of st and cvertices in both zigzag and armchair nanotubes, indicate that bond lengths are appr...

Unusual physical properties of single-wall carbon nanotubes have started a search for similar tubular structures of other elements. In this paper, we present a theoretical analysis of single-wall nanotubes of silicon and group-III-V compounds. Starting from precursor graphenelike structures we investigated the stability, energetics, and electronic structure of zigzag and armchair tubes using th...

We report structural, elastic, and electronic properties of selected, deformed, single-wall carbon nanotubes under uniaxial strain. We utilized a generalized gradient approximation potential of density functional theory and the linear combination of atomic orbital formalism. We discuss bond-lengths, tubule radii, and the band gaps as functions of tension and compression strain for carbon nanotu...

The fundamental question of how chirality affects the electronic coupling of a nanotube to metal contacts is important for tile application of nanotubes as nanowires. We show that metallic-zigzag nanotubes are superior to armchair nanotubes as nanowires, by modeling the metal-nanotube interfacc. More specifically, we show that as a function of coupling strength, the total electron transmission ...

With the advent of nanotechnology in the last decades, there has been an increased number of researches related to the development and application of nanostructures, in special, nanotube. The inorganic nanotubes, such as GaN, AlN and InN, have been studied due to their interesting characteristics, for instance good dielectric properties, good thermal conductivity [1], low displacement density, ...

in this paper an algorithm for computing the balaban and randic indices of any simple connected graph was introduced. also these indices were computed for ipr c80 fullerene isomers, zigzag nanotubes and graphene by gap program.

We have studied the behavior of band gap and effective mass of both the electrons and the holes in small diameter zigzag single-walled carbon nanotubes under uniaxial mechanical strain by using first-principles density-functional theory. The band gap of these nanotubes is modified by both compressive and tensile strain and all zigzag single-wall carbon nanotubes show a semiconductor-metal trans...