def load_rdkit_mol(cls, mol):
        """
        Create a :class:`MolecularSystem` from :class:`rdkit.Chem.rdchem.Mol`.

        Parameters
        ----------
        mol : :class:`rdkit.Chem.rdchem.Mol`
           An RDKit molecule object.

        Returns
        -------
        :class:`pywindow.molecular.MolecularSystem`
            :class:`MolecularSystem`

        """
        obj = cls()
        obj.system = obj._Input.load_rdkit_mol(mol)
        return obj