Fast hybrid density-functional computations using plane-wave basis sets

TL;DR

This paper introduces a fast, hybrid density-functional computational method using plane-wave basis sets, combining adaptively compressed exchange and orbital localization to significantly accelerate electronic structure calculations.

Contribution

The paper presents a novel implementation that integrates adaptively compressed exchange with orbital localization, achieving substantial speedups in plane-wave density functional computations.

Findings

Speedup of 3-4x in calculations

Effective for both molecular and periodic systems

Performance improves with system size

Abstract

A new, very fast, implementation of the exact (Fock) exchange operator for electronic structure calculations within the plane-wave pseudopotential method is described in detail for both molecular and periodic systems, and carefully validated. Our method combines the recently proposed Adaptively Compressed Exchange approach, to reduce the number of times the exchange is evaluated in the self-consistent loop, with an orbital localization procedure that reduces the number of exchange integrals to be computed at each evaluation and potentially the compute time of each of them. The new implementation, already available in the Quantum ESPRESSO distribution, results in a speedup that is never smaller than 3-4x and that increases with the size of the system, according to various realistic benchmark calculations.