Quantum ESPRESSO

This article is a draft

This is not a complete article: This is a draft, a work in progress that is intended to be published into an article, which may or may not be ready for inclusion in the main wiki. It should not necessarily be considered factual or authoritative.

Introduction

"Quantum ESPRESSO is an integrated suite of Open-Source computer codes for electronic-structure calculations and materials modeling at the nanoscale. It is based on density-functional theory, plane waves, and pseudopotentials."

"Quantum ESPRESSO has evolved into a distribution of independent and inter-operable codes in the spirit of an open-source project. The Quantum ESPRESSO distribution consists of a “historical” core set of components, and a set of plug-ins that perform more advanced tasks, plus a number of third-party packages designed to be inter-operable with the core components." (Description from Quantum ESPRESSO web site).

Running Quantum ESPRESSO

Use modules to choose a version. You can see available versions with module avail quantumespresso or module spider quantumespresso, and load one with (for example), module load quantumespresso/6.1.

Example job

File : qe_ex1.sh

#!/bin/bash
#SBATCH --account=def-someuser
#SBATCH --time=0-1:00           # DD-HH:MM
#SBATCH --nodes=2
#SBATCH --tasks-per-node=32     # MPI tasks
#SBATCH --mem=0                 # all memory on node
module load quantumespresso/6.1
srun pw.x < si.scf.in

The above example requests two whole nodes for a total of 64 processes. This is certainly more processors than is needed for the silicon tutorial case. Please be aware that suitable selection of a process count is complicated, but it is your responsibility to choose an efficient number. We recommend this lecture on parallelism in Quantum ESPRESSO.

Pseudopotentials

There is not currently a system-wide repository of pseudopotentials for Quantum ESPRESSO. You must find or create and store your own pseudopotential files.

Message Passing Interface