IOData.hetatm — whether to read HETATM records

If set to True, then all non-water 'HETATM' records are read from PDB or mmCIF files. (By default, only 'ATOM' records are read. To read waters, use IOData.water.) Note that you will usually need to turn this on when using BLK residues, or if you want to use a PDB or mmCIF file containing ligands.