def get_oxidation_state_decorated_structure(self):
        """
        Returns an oxidation state decorated structure.

        Returns:
            Returns an oxidation state decorated structure. Requires POTCAR
            to be supplied.
        """
        structure = self.chgcar.structure
        charges = [-self.get_charge_transfer(i)
                   for i in range(len(structure))]
        structure.add_oxidation_state_by_site(charges)
        return structure