The density-functional tight-binding (DFTB) formulation of the fragment molecular orbital method is combined with periodic boundary conditions. Long-range electrostatics and dispersion are evaluated Ewald summation technique. first analytic derivatives energy respect to atomic coordinates lattice parameters formulated. accuracy established in comparison numerical gradients DFTB without fragment...

In this work, we present a Grand Canonical Monte-Carlo simulation results for the adsorption of carbon vapour in the pores of faujasite zeolite (in its siliceous form). The carboncarbon interactions are described within the frame of a Tight Binding approach (fourth momentum’s method) while the carbon-zeolite interactions are modelled using a PN-TrAZ physisorption potential. Siliceous faujasite ...

In this work, charge transport (CT) properties of the p53 gene are numerically studied by the transfer matrix method, and using either single or double strand effective tight-binding models. A statistical analysis of the consequences of known p53 point mutations on CT features is performed. It is found that in contrast to other kind of mutation defects, cancerous mutations result in much weaker...

Optical absorption spectra of C 60 are theoretically investigated in order to analyze the optical properties of alkali metal doped fullerites A6C60. We use a tight binding model with long ranged Coulomb interactions and bond disorder. Optical spectra are obtained by the Hartree-Fock approximation and the CI method. The Coulomb interaction parameters which are relevant to the optical spectra of ...

Photonic crystal (PC) coupled cavity waveguides (CCWs) with completely separated eigenfrequencies (or supermodes) are investigated. Using a coupled mode theory, the properties of the supermodes, such as the electric field profiles, the eigenfrequencies (including the central frequencies and corresponding linewidths), and the quality factors (Qs) are expressed in very simple formulas, and these ...

In this paper energy bands and Berry curvature of graphene was studied. Desired Hamiltonian regarding the next-nearest neighbors obtained by tight binding model. By using the second quantization approach, the transformation matrix is calculated and the Hamiltonian of system is diagonalized. With this Hamiltonian, the band structure and wave function can be calculated. By using calculated wave f...