Write an ADF input file.

        Parameters
        ----------
        molecule : Molecule
            The molecule for this task.
        inpfile : str
            The name where the input file will be saved.

def write_file(self, molecule, inpfile):
        """
        Write an ADF input file.

        Parameters
        ----------
        molecule : Molecule
            The molecule for this task.
        inpfile : str
            The name where the input file will be saved.

        """

        mol_blocks = []
        atom_block = AdfKey("Atoms", options=["cartesian"])
        for site in molecule:
            atom_block.add_subkey(AdfKey(str(site.specie), list(site.coords)))
        mol_blocks.append(atom_block)

        if molecule.charge != 0:
            netq = molecule.charge
            ab = molecule.spin_multiplicity - 1
            charge_block = AdfKey("Charge", [netq, ab])
            mol_blocks.append(charge_block)
            if ab != 0:
                unres_block = AdfKey("Unrestricted")
                mol_blocks.append(unres_block)

        with open(inpfile, "w+") as f:
            for block in mol_blocks:
                f.write(str(block) + "\n")
            f.write(str(self.task) + "\n")
            f.write("END INPUT")