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.[1]
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.
#!/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
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.
Segfaults with OpenMPI 3.1.2
Users have reported random segfaults on Cedar when using Quantum ESPRESSO versions compiled for OpenMPI 3.1.2 in single-node jobs (shared memory communication). These issues seem not to happen with other versions of OpenMPI. If you experience such problems, first try to use an OpenMPI 2.1.1-based toolchain. For example:
[name@server ~]$ module load gcc/5.4.0
[name@server ~]$ module load openmpi/2.1.1
[name@server ~]$ module load quantumespresso/6.3
Parameter error in Grimme-D3
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.
[2]