Fast, efficient, and accurate dielectric screening using a local, real-space approach

Abstract

Various many-body perturbation theory techniques for calculating electron behavior rely on {\it W}, the screened Coulomb interaction. Computing {\it W} requires complete knowledge of the dielectric response of the electronic system, and the fidelity of the calculated dielectric response limits the reliability of predicted electronic and structural properties. As a simplification, calculations often begin with the random-phase approximation (RPA). However, even RPA calculations are costly and scale poorly, typically as $N^4$ ($N$ representing the system size). A local approach has been shown to be efficient while maintaining accuracy for screening core-level excitations [Ultramicroscopy {\bf 106}, 986 (2006)]. We extend this method to valence-level excitations. We present improvements to the accuracy and execution of this scheme, including reconstruction of the all-electron character of the pseudopotential-based wave functions, improved $N^2\log N$ scaling, and a parallelized implementation. We discuss applications to Bethe-Salpeter equation (BSE) calculations of core and valence spectroscopies.

References in corpus (9)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Advanced capabilities for materials modelling with Quantum ESPRESSO
• Many-body perturbation theory calculations using the yambo code
• Optical excitations in organic molecules, clusters and defects studied by first-principles Green's function methods
• Predictive GW calculations using plane waves and pseudopotentials
• Band convergence and linearization error correction of all-electron GW calculations: The extreme case of zinc oxide
• Accurate X-Ray Absorption Predictions for Transition Metal Oxides: An Advanced Self-Consistent-Field Approach Inspired by Many-Body Perturbation Theory
• Optical to UV spectra and birefringence of SiO${}_2$ and TiO${}_2$: First-principles calculations with excitonic effects
• Vibrational Effects in X-ray Absorption Spectra of 2D Layered Materials

Cited by in corpus (2)

• Multi-code Benchmark on Simulated Ti K-edge X-ray Absorption Spectra of Ti-O Compounds
• First-principles study of excitons in the optical spectra of silver chloride