Analysis of separable potentials

作者：Xavier Gonze, Roland Stumpf, Matthias Scheffler · 发表于：Physical review. B, Condensed matter · 年份：1991 · DOI：10.1103/physrevb.44.8503 · 被引用次数：604 · 研究领域：Advanced Chemical Physics Studies、High-pressure geophysics and materials、Advanced Physical and Chemical Molecular Interactions

Soft, fully separable ab initio pseudopotentials, introduced some years ago by Kleinman and Bylander [Phys. Rev. Lett. 48, 1425 (1982)], have proven to be very useful for large-scale electronic-structure and total-energy calculations. However, these pseudopotentials can induce unphysical results and destroy important chemical properties of the atom in the solid, if not constructed cautiously. We present here a detailed analysis of Kleinman-Bylander separable pseudopotentials. Two different techniques (a spectral investigation, and the logarithmic-derivative construction) allow a deeper understanding of their properties. It is shown how the above-mentioned problems can be avoided.