Black-box inhomogeneous preconditioning for self-consistent field iterations in density functional theory

TL;DR

This paper introduces a new, physically motivated preconditioner based on local density of states to improve convergence in self-consistent field iterations for diverse inhomogeneous systems in density functional theory.

Contribution

A novel, inexpensive preconditioner derived from the local density of states that effectively addresses charge sloshing in large, inhomogeneous systems within density functional theory.

Findings

Successfully tested on systems with metals, insulators, semiconductors, and vacuum.

Cures long-range charge sloshing in large inhomogeneous systems.

Applicable to both metals and insulators, extendable to semiconductors.

Abstract

We propose a new preconditioner based on the local density of states for computing the self-consistent problem in Kohn-Sham density functional theory. This preconditioner is inexpensive and able to cure the long-range charge sloshing known to hamper convergence in large, inhomogeneous systems such as clusters and surfaces. It is based on a parameter-free and physically motivated approximation to the independent-particle susceptibility operator, appropriate for both metals and insulators. It can be extended to semiconductors by using the macroscopic electronic dielectric constant as a parameter in the model. We test our preconditioner successfully on inhomogeneous systems containing metals, insulators, semiconductors and vacuum.