Calculation of Atomic Energy Levels by Using a Fully-Coupled Solver for the Kohn-Sham Equation and the Poisson Equation

Abstract

In this work, a density-functional theory calculation of atomic energy levels is performed. Two equations in the density-functional theory, the Kohn-Sham equation and the Poisson equation, are fully coupled. The static dielectric function is accurately evaluated. By considering the exact dielectric function in the self-consistent field loop, the convergence behavior of the Newton-Raphson method is greatly improved. It is expected that this approach can be extended to the calculation of the band structure of crystalline materials.