arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1402.7366cond-mat.mtrl-sciphysics.comp-ph
收藏

Shirley降阶基:平面波DFT的降阶模型

The Shirley reduced basis: a reduced order model for plane-wave DFT

Maxwell Hutchinson, David Prendergast

摘要:

Shirley约化基(SRB)将Bloch函数的周期部分表示为从布里渊区的粗样本中提取的本征向量的线性组合,通过适当的正交分解正交化和约化。我们描述了一种新的变换的自洽密度泛函理论的问题,从一个平面波基与超软赝势的SRB是独立的k点。特别地,在平面波空间上的操作的数量与k点的数量无关。探讨了变换的参数空间,并提出了合适的缺省值。SRB收敛到平面波解。对于降维系统,与平面波计算相比,计算成本降低超过5倍。在类似分子动力学的环境中,本体系统的性能提高了1.67倍。这种稳健的技术非常适合于对电子能带结构中的细微细节(例如拓扑绝缘体、狄拉克半金属、金属表面和纳米结构)以及与这些系统中的任何系统的界面处的电荷转移具有严格要求的系统的有效研究。用于实现k独立变换的技术可以应用于其他计算昂贵的矩阵元素,例如密度泛函微扰理论和多体微扰理论中的那些。

英文摘要:

The Shirley reduced basis (SRB) represents the periodic parts of Bloch functions as linear combi- nations of eigenvectors taken from a coarse sample of the Brillouin zone, orthogonalized and reduced through proper orthogonal decomposition. We describe a novel transformation of the self-consistent density functional theory eigenproblem from a plane-wave basis with ultra-soft pseudopotentials to the SRB that is independent of the k-point. In particular, the number of operations over the space of plane-waves is independent of the number of k-points. The parameter space of the transformation is explored and suitable defaults are proposed. The SRB is shown to converge to the plane-wave solution. For reduced dimensional systems, reductions in computational cost, compared to the plane-wave calculations, exceed 5x. Performance on bulk systems improves by 1.67x in molecular dynamics-like contexts. This robust technique is well-suited to efficient study of systems with strin- gent requirements on numerical accuracy related to subtle details in the electronic band structure, such as topological insulators, Dirac semi-metals, metal surfaces and nanostructures, and charge transfer at interfaces with any of these systems. The techniques used to achieve a k-independent transformation could be applied to other computationally expensive matrix elements, such as those found in density functional perturbation theory and many-body perturbation theory.

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。

↑