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arXiv 2005.07834cond-mat.mtrl-sci
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使用局部实空间方法快速、高效、准确地进行介质筛选

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

John Vinson, Eric L. Shirley

摘要:

计算电子行为的各种多体微扰理论技术依赖于{ \it W},屏蔽库仑相互作用。计算{ \it W}需要完全了解电子系统的介电响应,并且计算的介电响应的保真度限制了预测的电子和结构性质的可靠性。作为一种简化,计算通常从随机相位近似(RPA)开始。然而,即使RPA计算也是昂贵的,并且扩展性差,通常为$N^4$($N$表示系统大小)。局部方法已被证明是有效的,同时保持筛选核心水平激发的准确性[Ultramicroscopy { \bf 106},986(2006)]。我们将这种方法推广到价态激发。我们提出了改进的准确性和执行这个计划,包括重建的全电子字符的赝势为基础的波函数,改进的$N^2\log N$缩放,和并行实现。我们讨论了应用Bethe-Salpeter方程(BSE)计算的核心和价光谱。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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