In this article, the crystallization of polyethylene is investigated by the modified weighted density approximation. Also, a direct correlation function of polyethylene based on the RISM theory is used. The free energy of a polyethylene is calculated using the density functional theory. The crystallization and also the solid and liquid densities of polyethylene are calculated and compared...

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...

in order to study some theories about nonsuperconductivity of prba2cu3o7, based on the density functional theory and with apw+lo/lapw method some calculations for prba2cu3o7 (pr123) and yba2cu3o7 (y123) were performed. the lsda+u approximation was used for pr(4f) orbitals and the effect of changing upr on the band structure, pr(4f)-dos, distribution of electrons on the planes and chains, and pr...

potassium alanate is one of the goal candidates for hydrogen storage during past decades. in this report, initially the density functional theory was applied to simulate the electronic and structural characteristic of the experimentally known kalh4 complex hydride. the relaxation of unit cell parameters and atomic positions was performed until the total residual force reduced less than 0.001ev ...

density functional theory (dft) calculations have been performed to investigating the effects of themolecular oxygen impurity on the quadrupole coupling constant (qcc) parameters of armchair and zigzagboron nitride nanotubes (bnnts). optimization processes have been performed to relax the original andimpure structures of the investigated bnnts. afterwards, the qcc parameters have been evaluated...

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 ...

Ivan A. Larkin†and L. S. Levitov‡ †Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK ‡Center for Materials Science & Engineering, Physics Department, MIT, Cambridge, MA-02139 Abstract The incompressible Quantum Hall strip is sensitive to charging of localized states in the cyclotron gap. We study the effect of localized states by a density functional approach an...