We develop a technique for generating a set of optimized local basis functions to solve models in the Kohn–Sham density functional theory for both insulating and metallic systems. The optimized local basis functions are obtained by solving a minimization problem in an admissible set determined by a large number of primitive basis functions. Using the optimized local basis set, the electron ener...

A short review of recent theoretical advances in studies of the interaction between highly charged systems is presented. Such a system could not be described by the mean field theory. More advanced methods have to be used in order to introduce the correlations between highly charged particles. In this work I focus on the system of highly charged surfaces, separated by a solution of molecules wi...

The flexoelectric effect for pear-shaped molecules was studied within NPT Monte Carlo simulations. The asymmetric molecules were modelled by a heterogenic two-site pair potential consisting of rigidly connected Gay-Berne and Lennard-Jones particles, thus giving rise to a steric dipolar moment. The simulation data for order parameters and pair correlation functions were used within a density fun...

We have developed an efficient computational scheme utilizing the real-space finite-difference formalism and the projector augmented-wave PAW method to perform precise first-principles electronic-structure simulations based on the density-functional theory for systems containing transition metals with a modest computational effort. By combining the advantages of the time-saving double-grid tech...

A recently proposed linear-scaling scheme for density-functional pseudopotential calculations is described in detail. The method is based on a formulation of density functional theory in which the ground state energy is determined by minimization with respect to the density matrix, subject to the condition that the eigenvalues of the latter lie in the range [0,1]. Linear-scaling behavior is ach...

the present study aims to investigate the association between emotional-functional evelopment and formation of creative thinking among children of 4-6 years old in mashhad city. to do this, 80 children and their mothers were selected from preschools of mashhad city based on cluster sampling method.  the level of creativity among children was measured through torrance test of critical thinking (...

In this paper, we study dynamic commensalism model with nonmonotic functional response, density dependent birth rates on time scales and derive sufficient conditions for the permanence. We also establish the existence and uniform asymptotic stability of unique almost periodic positive solution of the model by using Lyapunov functional method.

  Abstract   Background : Although, different studies on end-to-side nerve repair, results are controversial. The importance of this method in case is unavailability of proximal nerve. In this method, donor nerves also remain intact and without injury. In compare to other classic procedures, end-to-side repair is not much time consuming and needs less dissection. Overall, the previous studies i...