Body
Avogadro is available through Open OnDemand for building, editing and viewing molecules.
To start it, go to ood.fit.edu, open Interactive Apps, and choose Avogadro. Set a GPU count of 1 on the form so the 3D view runs on the graphics hardware.
The first time you launch it, Avogadro offers to set up a Python environment for its input file generators. Answer yes. It takes a few seconds and needs no network access. Those generators build input files for ORCA and NWChem, both of which are installed on the cluster.
Avogadro is an editor rather than a solver, so the session is sized smaller than the other apps and is capped at 24 hours. Build your structure here, then submit the calculation itself as a batch job.