====== QuantumATK on DARWIN ======

Use ''vpkg_versions quantum-atk'' to see a list of all available versions of QuantumATK installed on DARWIN. For example 

<code bash>
$ vpkg_versions quantum-atk

Available versions in package (* = default version):

[/opt/shared/valet/2.1/etc/quantum-atk.vpkg_yaml]
quantum-atk           Atomistic Simulation Software
* 2023.12             version 2023.12 for Linux (with bundled MPI)
  2023.12:system-mpi  version 2023.12 for Linux (no bundled MPI)
</code>

The VALET package for Quantum ATK is available to everyone on DARWIN, however QuantumATK requires user(s) to purchase a license and setup a license server to actually use the software.

===== Available to entire workgroup =====

This requires some amount of setup for each workgroup in order to use QuantumATK on DARWIN.  If access should be available to everyone in the workgroup:

  - Create a file called ''${WORKDIR}/sw/quantum-atk/license-server''
  - Add the appropriate //license server path// (''<port>@<hostname>'') to that file

The Quantum ATK VALET package checks for this ''license-server'' file and sets the ''SNPSLMD_LICENSE_FILE'' environment variable to its content.  Storing the ''license-server'' file in the ''${WORKDIR}'' directory limits access to member of the workgroup.

===== Available to individuals =====

If only individual workgroup users are allowed to use the software, then each user must set the ''SNPSLMD_LICENSE_FILE'' environment variable either in:

  * the ''~/.bashrc'' file
  * each job script

The value of the variable is the //license server path//, e.g.

<code bash>
export SNPSLMD_LICENSE_FILE=<port>@<hostname>
</code>

===== Job script template and examples =====

A job script template is available at ''/opt/templates/slurm/applications/quantum-atk.qs'' for execution of ATK Python scripts.  Users should make a copy of this template and edit according to each job.  Execution of several ATK example jobs can be found in ''/opt/shared/quantum-atk/examples''.