Nonlocal kinetic energy density functionals for isolated systems obtained via local density approximation kernels
Qiang Xu, Jian Lv, Yanchao Wang, Yanming Ma
Abstract
Despite a large number of nonlocal kinetic energy density functionals (KEDFs) available for large-scale calculations, most of those nonlocal KEDFs designed for the extended systems can not be directly applied to isolated systems. In this paper we propose a generalized scheme to construct nonlocal KEDFs via the local density approximation kernels and construct a family of KEDFs for simulations of isolated systems. We have implemented these KEDFs into our developed atlas software for numerical calculations of isolated systems within orbital-free density-functional theory. The performance of KEDFs has been demonstrated by several clusters encompassing Mg, Si, and GaAs. The results show that our constructed KEDFs can achieve high numerical accuracy and stability for random clusters, therefore, making orbital-free density-functional theory accessible for practical simulations of isolated systems.