Resta-like preconditioning for self-consistent field iterations in the linearized augmented planewave method

TL;DR

This paper introduces a Resta-like preconditioning method for the LAPW approach to improve convergence in self-consistent field cycles of density-functional theory calculations, especially for semiconducting systems.

Contribution

The paper develops and implements a new preconditioning scheme in the LAPW method that enhances convergence efficiency and reliability across different material systems.

Findings

Reliable convergence in semiconductors and metals

Improved efficiency over Kerker preconditioner

Effective suppression of charge sloshing

Abstract

Convergence in self-consistent-field cycles can be a major computational bottleneck of density-functional theory calculations. We propose a Resta-like preconditioning method for full-potential all-electron calculations in the linearized augmented planewave (LAPW) method to smoothly converge to self-consistency. We implemented this preconditioner in the exciting code and apply it to the two semiconducting systems of MoS$_2$ slabs and P-rich GaP(100) surfaces as well as the metallic system Au(111), containing a sufficiently large amount of vacuum. Our calculations demonstrate that the implemented scheme performs reliably as well as more efficiently regardless of system size, suppressing long-range charge sloshing. While the suitability of this preconditioning higher for semiconducting systems, the convergence for metals is only slightly decreased and thus still trustworthy to apply. Furthermore, a mixing algorithm with the preconditioner shows an improvement over that with the Kerker preconditioner for the investigated semiconducting systems.