Quantum ESPRESSO

Description

Quantum ESPRESSO (QE) is an integrated suite of codes for electronic structure calculations and materials modeling at the nanoscale, based on DFT, plane waves, and pseudopotentials. QE is an open initiative, in collaboration with many groups world-wide, coordinated by the Quantum ESPRESSO Foundation.

Documentation and other material can be found on the QE website.

Prerequisites

QE is free software, released under the GNU General Public License (v2). Scientific work done using the QE code should contain citations of corresponding QE references.

Only members of the q_espr user group have access to QE executables provided by HLRN. To have their user ID included in this group, users can send a message to their consultant or to HLRN support.

Modules

The environment modules shown in the table below are available to include executables of the QE distribution in the directory search path. To see what is installed and what is the current default version of QE at HLRN, a corresponding overview can be obtained by saying module avail qe.

QE is a hybrid MPI/OpenMP parallel application. It is recommended to use mpirun as the job starter for QE at HLRN. An MPI module providing the mpirun command needs to be loaded ahead of the QE module.

Job Script Examples

1. For Intel Cascade Lake compute nodes – plain MPI case (no OpenMP threading) of a QE job using a total of 1152 CPU cores distributed over 12 nodes, 96 tasks each. Here 3 pools (nk=3) are created for k-point parallelization (384 tasks per k-point), 3D-FFT is performed using 8 task groups (48 tasks each, nt=8).

   #!/bin/bash
   #SBATCH -t 12:00:00
   #SBATCH -p standard96
   #SBATCH -N 12
   #SBATCH --tasks-per-node 96
    
   module load impi/2018.5
   module load qe/6.4.1
   
   export SLURM_CPU_BIND=none
   export OMP_NUM_THREADS=1
   
   mpirun pw.x -nk 3 -nt 8 -i inputfile > outputfile