Quantum ESPRESSO

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. Quantum ESPRESSO web site.

Usage

To use Quantum ESPRESSO, you need to load a module (see Using modules). You can see available versions using module avail quantumespresso or module spider quantumespresso, and load one with (for example), module load quantumespresso/6.6.

qe_ex1.sh

#!/bin/bash
#SBATCH --account=def-someuser
#SBATCH --time=0-1:00           # DD-HH:MM
#SBATCH --nodes=1
#SBATCH --tasks-per-node=32     # MPI tasks
#SBATCH --mem=0                 # all memory on node
module load StdEnv/2020  intel/2020.1.217  openmpi/4.0.3
module load quantumespresso/6.6
srun pw.x < si.scf.in > si.scf.out

Note

The above example requests 32 processes, which is more than 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. See also Advanced MPI scheduling.

Known problems

No pseudopotential files

There is no system-wide repository of pseudopotentials for Quantum ESPRESSO on our clusters. You must find or create and store your own pseudopotential files.

Parameter error in Grimme-D3

Warning

Incorrect results may be obtained when running Grimme-D3 with the element barium (Ba). The error comes from an incorrect value for one of the coefficients for barium, specifically, the r2r4 parameter in the source code file dft-d3/core.f90. The correct value should be 10.15679528, not 0.15679528. The error has been confirmed by the QE developers to exist in all versions from 6.2.1 to 7.1. "Wrong r2r4 value for Ba in the dft-d3 code", Quantum ESPRESSO mailing list, 2022 July 9.