QE/EPW tips and tricks

Last updated: Fri Jun 23, 2023 - Fixed instructions from 2023-02-20 based on Ubuntu 22.04, which was installed in all Sysnet-owned workstations in Fall 2022.

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 to be able to load compiler modules.

    • issue module load compiler to get access to ifort and icc.

    • issue module load mpi to load MPI modules.

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

    • issue module load mkl to load libraries.

  • Issue ./configure

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

  • Issue make epw

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.