A PDB2PQR .DAT file has the following whitespace-delimited columns:
- Name of the residue (:py:class:`str`, e.g., RU, ARG, WAT, etc.)
- Name of the atom (:py:class:`str`, e.g., HB3, CA, HA, etc.)
- Charge of the atom (:py:class:`float`, in electrons)
- Radius of the atom (:py:class:`float`, in Å)
- (optional) Atom type (:py:class:`str`, e.g., HT, etc.)
Lines that start with # are treated as comments.