Allow ion forumulae to be null e.g. in non-RCSB PDB files / files missing headers. Adding consistency check for the ligand mapping i.e. ensure we always map ABC to XYZ regardless of ligand instance.
Allow ion forumulae to be null e.g. in non-RCSB PDB files / files missing headers.
Adding consistency check for the ligand mapping i.e. ensure we always map ABC to XYZ regardless of ligand instance.

Kortemme-Lab/klab,Kortemme-Lab/klab,Kortemme-Lab/klab,Kortemme-Lab/klab