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

Article

关键词: INTERATOMIC FORCE-CONSTANTS;    ELECTRON-GAS;    CORE-HOLE;    GREENS-FUNCTION;    1ST PRINCIPLES;    SELF-ENERGIES;    TIME METHOD;    SEMICONDUCTORS;    EXCITATIONS;    POINTS;   

DOI  :  10.1103/PhysRevB.103.245143

来源: SCIE

【 摘 要 】

Various many-body perturbation theory techniques for calculating electron behavior rely on W, the screened Coulomb interaction. Computing 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 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 calculations of core and valence spectroscopies.

【 授权许可】

Free