Quantum ESPRESSO

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