Efficient single-grid and multi-grid solvers for real-space orbital-free density functional theory

To improve the computational efficiencies of real-space orbital-free density functional theory, this work develops a new single-grid solver by directly providing closed-form solution to inner iteration and using an improved bisection method accelerate line search process in outer iteration, extended multi-grid solver. Numerical examples show that while maintaining high level accuracy, proposed can two orders magnitude comparing with methods literature (For example, ground state energy 45×45×45 FCC Aluminum cluster (376786 atoms) be computed within 4h27min on desktop computer.) even once for cases where high-resolution electron densities are needed.