Uses OpenBabel to output all supported formats.

        Args:
            filename: Filename of file to output
            file_format: String specifying any OpenBabel supported formats.

def write_file(self, filename, file_format="xyz"):
        """
        Uses OpenBabel to output all supported formats.

        Args:
            filename: Filename of file to output
            file_format: String specifying any OpenBabel supported formats.
        """
        mol = pb.Molecule(self._obmol)
        return mol.write(file_format, filename, overwrite=True)