Add a folder src with a git clone of cq inside.

.
├── build.sh
├── image
└── src
    └── chronusq_dev

Modify the git checkout branch in image file.

See run.sh on how to execute the calculations

apptainer exec cq.sif chronusq -i test.inp

This is a no MPI build though I plan to add MPI support once I need it. Interestingly adding MPI support through a container incurs no (or nearly no) overhead (see https://www.youtube.com/watch?v=oMEQGEUauwQ).