Jing Xin, Suryanarayana Phanish
College of Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
College of Computing, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
J Chem Phys. 2024 Aug 28;161(8). doi: 10.1063/5.0225396.
We present an efficient real space formalism for hybrid exchange-correlation functionals in generalized Kohn-Sham density functional theory (DFT). In particular, we develop an efficient representation for any function of the real space finite-difference Laplacian matrix by leveraging its Kronecker product structure, thereby enabling the time to solution of associated linear systems to be highly competitive with the fast Fourier transform scheme while not imposing any restrictions on the boundary conditions. We implement this formalism for both the unscreened and range-separated variants of hybrid functionals. We verify its accuracy and efficiency through comparisons with established planewave codes for isolated as well as bulk systems. In particular, we demonstrate up to an order-of-magnitude speedup in time to solution for the real space method. We also apply the framework to study the structure of liquid water using ab initio molecular dynamics, where we find good agreement with the literature. Overall, the current formalism provides an avenue for efficient real-space DFT calculations with hybrid density functionals.
我们提出了一种用于广义Kohn-Sham密度泛函理论（DFT）中杂化交换关联泛函的高效实空间形式。特别是，我们通过利用实空间有限差分拉普拉斯矩阵的克罗内克积结构，为其任何函数开发了一种高效表示，从而使相关线性系统的求解时间与快速傅里叶变换方案具有高度竞争力，同时不对边界条件施加任何限制。我们针对杂化泛函的无屏蔽和范围分离变体实现了这种形式。我们通过与用于孤立和体系统的既定平面波代码进行比较，验证了其准确性和效率。特别是，我们展示了实空间方法在求解时间上加快了高达一个数量级。我们还应用该框架使用从头算分子动力学研究液态水的结构，在那里我们发现与文献有很好的一致性。总体而言，当前的形式为使用杂化密度泛函进行高效的实空间DFT计算提供了一条途径。
