论文标题
快速，高效且准确的介电筛选使用局部真实空间方法
Fast, efficient, and accurate dielectric screening using a local, real-space approach
论文作者
论文摘要
用于计算电子行为的各种多体扰动理论技术依赖于{\ it W}，这是筛选的库仑相互作用。计算{\ it W}需要完全了解电子系统的介电响应，并且计算出的介电响应的保真度限制了预测的电子和结构性能的可靠性。简而言之，计算通常始于随机相近似（RPA）。但是，即使是RPA计算的成本高昂且规模较差，通常为$ n^4 $（代表系统大小的$ n $）。已经证明，一种局部方法是有效的，同时保持了筛选核心水平激发的精度[超显微镜{\ bf 106}，986（2006）]。我们将此方法扩展到价级激发。我们介绍了该方案准确性和执行的改进，包括重建基于伪能力的波函数的全电子特征，改进了$ n^2 \ log n $缩放以及并行化的实现。我们讨论了核心和价光谱的伯特 - 盐方程（BSE）计算的应用。
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.
