Exact Coulomb cutoff technique for supercell calculations

Exact Coulomb cutoff technique for supercell calculations

Carlo A. Rozzi,1,2 Daniele Varsano,3,2 Andrea Marini,4,2 Eberhard K. U. Gross,1,2 and Angel Rubio1,3,2 1Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany 2European Theoretical Spectroscopy Facility (ETSF), D-14195 Berlin, Germany and E-20018 San Sebastián, Spain 3Departamento de Física de Materiales, Facultad de Ciencias Químicas, UPV/EHU, Centro...

Spectral bounds for the cutoff Coulomb potential

The method of potential envelopes is used to analyse the bound-state spectrum of the Schrödinger Hamiltonian H = −∆− v/(r+ b) , where v and b are positive. We established simple formulas yielding upper and lower energy bounds for all the energy eigenvalues. PACS 31.15.Gy, 31.15.Pf, 03.65.Ge. Spectral bounds for the cutoff Coulomb potential page 2

Ewald Summation for Coulomb Interactions in a Periodic Supercell

Approximate bandstructures of semiconductor alloys from tight-binding supercell calculations

Alloys such as AlGaAs, InGaAs, and SiGe find widespread usage in nanoelectronic devices such as quantum dots and nanowires. For these devices, in which the carriers probe nanometre-scale local disorder, the commonly employed virtual crystal approximation (VCA) is inadequate. Although the VCA produces small-cell E(k) relations it fails to include local disorder. In contrast, random-alloy superce...

Exact Failure Frequency Calculations for Extended Systems

This paper shows how the steady-state availability and failure frequency can be calculated in a single pass for very large systems, when the availability is expressed as a product of matrices. We apply the general procedure to k-out-of-n:G and linear consecutive k-out-of-n:F systems, and to a simple ladder network in which each edge and node may fail. We also give the associated generating func...