Get RMSD between two molecule with arbitrary atom order.

        Returns:
            RMSD if topology of the two molecules are the same
            Infinite if  the topology is different

def get_rmsd(self, mol1, mol2):
        """
        Get RMSD between two molecule with arbitrary atom order.

        Returns:
            RMSD if topology of the two molecules are the same
            Infinite if  the topology is different
        """
        label1, label2 = self._mapper.uniform_labels(mol1, mol2)
        if label1 is None or label2 is None:
            return float("Inf")
        return self._calc_rms(mol1, mol2, label1, label2)