Running Fleur

This section adresses the question of how to run Fleur "by hand". If one is interested in running Fleur in a scripting environment the AiiDA plug-in should be considered.

There are several executables created in the build process:

and one of:

In most cases you will first run the input generator to create an inp.xml.

Afterwards you will run fleur or fleur_MPI using this inp.xml file. Please note that the Fleur executable will always read its input from an inp.xml file in the current directory.

Command line options

The run-time behaviour of Fleur can be modified using command line switches. These switches modify the way Fleur might operate or in some cases determine what Fleur actually does. If you want to change the calculation setup you should modify the inp.xml file.

In the following the most relevant command line options are listed. For a full list of available options, please run fleur -h

General options:

Options controlling the IO of eigenvectors/values: (not all are available if you did not compile with the required libraries)

Options controlling the Diagonalization: (not all are available if you did not compile with the required libraries)

Environment Variables

There are basically two environments variables you might want to change when using Fleur.

Starting Fleur with MPI parallelization

While the OpenMP parallelization is controlled with the environment variable mentioned above or other external settings the degree of MPI parallelization is controlled in the command line call to the MPI executable of Fleur. Typically fleur_MPI is provided as a command-line argument to the respective MPI executable mpirun, mpiexec, srun, or similar. The degree of MPI parallelization is also a command-line argument to the respective MPI executable. Please be aware that invoking such an executable with the non-MPI-parallelized version of Fleur will yield Fleur errors. The distribution of the Fleur calculation onto different compute nodes of a cluster is typically set by the respective variables in a Jobfile for the used queueing system.

For a guide on how to choose good parallelization schemes please have a look at the respective section.