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[edit]
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[edit]
No pseudopotential files[edit]
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[edit]
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[edit]
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]