一种高效的用于大分子体系的密度泛函理论力场评估方法。

An efficient density-functional-theory force evaluation for large molecular systems.

机构信息

Department of Chemistry, Centre for Theoretical and Computational Chemistry, University of Oslo, P.O. Box 1033 Blindern, N-0315 Oslo, Norway.

出版信息

J Chem Phys. 2010 Jul 28;133(4):044102. doi: 10.1063/1.3459061.

DOI:10.1063/1.3459061

PMID:20687628

Abstract

An efficient, linear-scaling implementation of Kohn-Sham density-functional theory for the calculation of molecular forces for systems containing hundreds of atoms is presented. The density-fitted Coulomb force contribution is calculated in linear time by combining atomic integral screening with the continuous fast multipole method. For higher efficiency and greater simplicity, the near-field Coulomb force contribution is calculated by expanding the solid-harmonic Gaussian basis functions in Hermite rather than Cartesian Gaussians. The efficiency and linear complexity of the molecular-force evaluation is demonstrated by sample calculations and applied to the geometry optimization of a few selected large systems.

摘要

本文提出了一种高效、线性标度的 Kohn-Sham 密度泛函理论实现方法，用于计算含有数百个原子的体系的分子力。通过原子积分屏蔽与连续快速多极方法相结合，在线性时间内计算密度拟合库仑力贡献。为了提高效率和简化计算，近场库仑力贡献通过在 Hermite 而不是笛卡尔高斯中展开固体调和高斯基函数来计算。通过示例计算证明了分子力评估的效率和线性复杂度，并将其应用于几个选定的大型体系的几何优化。