Improved treatment of exact exchange in Quantum ESPRESSO

Taylor A. Barnes, Thorsten Kurth, Pierre Carrier, Nathan Wichmann, David Prendergast, Paul R.C. Kent, Jack Deslippe

Research output: Contribution to journalArticlepeer-review

35 Scopus citations

Abstract

We present an algorithm and implementation for the parallel computation of exact exchange in Quantum ESPRESSO (QE) that exhibits greatly improved strong scaling. QE is an open-source software package for electronic structure calculations using plane wave density functional theory, and supports the use of local, semi-local, and hybrid DFT functionals. Wider application of hybrid functionals is desirable for the improved simulation of electronic band energy alignments and thermodynamic properties, but the computational complexity of evaluating the exact exchange potential limits the practical application of hybrid functionals to large systems and requires efficient implementations. We demonstrate that existing implementations of hybrid DFT that utilize a single data structure for both the local and exact exchange regions of the code are significantly limited in the degree of parallelization achievable. We present a band-pair parallelization approach, in which the calculation of exact exchange is parallelized and evaluated independently from the parallelization of the remainder of the calculation, with the wavefunction data being efficiently transformed on-the-fly into a form that is optimal for each part of the calculation. For a 64 water molecule supercell, our new algorithm reduces the overall time to solution by nearly an order of magnitude.

Original languageEnglish
Pages (from-to)52-58
Number of pages7
JournalComputer Physics Communications
Volume214
DOIs
StatePublished - May 1 2017

Funding

Work by DP was conducted at The Molecular Foundry, which is supported by the Office of Science, Office of Basic Energy Sciences of the United States Department of Energy under Contract No. DE-AC02-05CH11231.

FundersFunder number
U.S. Department of EnergyDE-AC02-05CH11231
Office of Science
Basic Energy Sciences

    Keywords

    • Hybrid DFT
    • Quantum ESPRESSO
    • Scalability

    Fingerprint

    Dive into the research topics of 'Improved treatment of exact exchange in Quantum ESPRESSO'. Together they form a unique fingerprint.

    Cite this