Singularity images for Quantum Package

Requirements for build

• Singularity >= 3.0

Build qp2_pure.sif container

The qp2_pure.def file contains isntructions to build a Singularity image from the Ubuntu base with development branch of Quantum Package and with TREXIO library (v.2.1.0) installed in it.

To build the container, run:

singularity build --fakeroot qp2_pure.sif qp2_pure.def

In recent container images, --fakeroot allows to have root priviliges within the container at build time without the need to run sudo singularity. It is considered a good practice since it does not grant the sudo access to the container on the host system and, thus, more secure.

Build qp2_trexio.sif container

The qp2_trexio.def file contains isntructions to build a Singularity image using previously built qp2_pure.sif image as a base. This image will contain the trexio plugin of Quantum Package (cloned and installed from qp_plugins_scemama GitLab repository), which is needed to produce TREXIO files from the QP-native EZFIO format.

To build the container, run:

singularity build --fakeroot --force qp2_trexio.sif qp2_trexio.def

Here --force option is needed to overwrite the %labels and %help attributes of the existing container with the ones coming from the qp2_trexio.def definition file.

Run the containers

The aforementioned containers can be executed either in an interactive shell, e.g.

singularity shell qp2_trexio.sif

or as a stand-alone qpsh application using

singularity run qp2_trexio.sif <qp2_commands_script>

(or equivalently singularity exec qp2_trexio.sif /qp2/bin/qpsh <qp2_commands_script>)

By default, Singularity mounts the current directory ($PWD), $HOME and /tmp/ directories of the host system at runtime. It will also load the environment variables from the host system. For better reproducibility, one can use --no-home and/or --cleanenv options at run time. The former disables mounting of the host $HOME directory, while the latter skips loading of the host environment variables. For example,

singularity run --no-home --cleanenv qp2_trexio.sif <qp2_commands_script>

Note: if the <qp2_commands_script> file is in a directory under $HOME than it will not be visible when using --no-home option.