QE/EPW tips and tricks

Last updated: Mon Nov 17, 2025 - Fixed instructions from 2023-06-23, which loaded incompatible modules to render certain libraries undisoverable by ./configure.

0. Compilation on local cluster

  • Download the latest version from epw-code.org or clone from GitLab.

  • Unpack and configure QuantumEspresso using tar xvfz q-e/ then move into the new folder with cd q-e/

  • Make sure to load all required modules. Do the following in order:

    • issue module purge to start from a clean state.

      • If module command is not available, refer to this help page for instructions.

    • issue module load intel/2022, which gives access to mpiifort among other things.

    • issue module load mkl to load libraries.

    • issue module load mpi to load MPI modules.

      • As of 23 Jun 2023, neither mpich2 nor openmpi is available to load.

    • issue module load icc/2022.

    • issue ulimit -s unlimited. TODO: Explain what this does

  • Issue ./configure

  • Check make.inc file if the correct compilers are selected

  • Issue make -j8 epw

    • Change the number of processes to use in compiling as you wish (e.g., -j16).

NOTE: When executing QuantumEspresso, the same module files have to be loaded as when you compiled it.

1. Issues Running QE and Solutions

  • Large supercell calculations

    • Memory issues: Increase number of nodes, decrease parallelization levels, or use large-memory nodes (nvdimm queue on Frontera)

    • Diagonalization taking too much time: If diagonalization is taking a long time, it’s possible that ‘diago_thr_init’ (diagonalization threshold) is too small by default, because it scales as 1/n_elec. Manually setting it to higher values can avoid such issues, but one must verify the accuracy of the resulting calculation.