Na3Ce5Cl18 crystallizes in the hexagonal P-6 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 9-coordinate geometry to three equivalent Cl(4) and six equivalent Cl(2) atoms. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to three equivalent Cl(2) and three equivalent Cl(4) atoms. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 9-coordinate geometry to three equivalent Cl(1), three equivalent Cl(2), and three equivalent Cl(3) atoms. In the second Ce site, Ce(2) is bonded in a 9-coordinate geometry to three equivalent Cl(2), three equivalent Cl(3), and three equivalent Cl(4) atoms. In the third Ce site, Ce(3) is bonded in a 9-coordinate geometry to three equivalent Cl(1) and six equivalent Cl(3) atoms. There are four inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a trigonal non-coplanar geometry to one Ce(3) and two equivalent Ce(1) atoms. In the second Cl site, Cl(2) is bonded to one Na(1), one Na(2), one Ce(1), and one Ce(2) atom to form ClNa2Ce2 tetrahedra that share corners with three equivalent Cl(4)Na3Ce2 square pyramids, corners with seven equivalent Cl(2)Na2Ce2 tetrahedra, edges with three equivalent Cl(4)Na3Ce2 square pyramids, and edges with two equivalent Cl(2)Na2Ce2 tetrahedra. In the third Cl site, Cl(3) is bonded in a trigonal non-coplanar geometry to one Ce(1), one Ce(2), and one Ce(3) atom. In the fourth Cl site, Cl(4) is bonded to one Na(1), two equivalent Na(2), and two equivalent Ce(2) atoms to form distorted ClNa3Ce2 square pyramids that share corners with two equivalent Cl(4)Na3Ce2 square pyramids, corners with six equivalent Cl(2)Na2Ce2 tetrahedra, edges with four equivalent Cl(4)Na3Ce2 square pyramids, and edges with six equivalent Cl(2)Na2Ce2 tetrahedra.
Na3Ce5Cl18 crystallizes in the hexagonal P-6 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 9-coordinate geometry to three equivalent Cl(4) and six equivalent Cl(2) atoms. All Na(1)-Cl(4) bond lengths are 3.11 Å. All Na(1)-Cl(2) bond lengths are 3.04 Å. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to three equivalent Cl(2) and three equivalent Cl(4) atoms. All Na(2)-Cl(2) bond lengths are 2.76 Å. All Na(2)-Cl(4) bond lengths are 3.17 Å. There are three inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 9-coordinate geometry to three equivalent Cl(1), three equivalent Cl(2), and three equivalent Cl(3) atoms. All Ce(1)-Cl(1) bond lengths are 2.93 Å. All Ce(1)-Cl(2) bond lengths are 2.91 Å. All Ce(1)-Cl(3) bond lengths are 3.00 Å. In the second Ce site, Ce(2) is bonded in a 9-coordinate geometry to three equivalent Cl(2), three equivalent Cl(3), and three equivalent Cl(4) atoms. All Ce(2)-Cl(2) bond lengths are 2.94 Å. All Ce(2)-Cl(3) bond lengths are 2.97 Å. All Ce(2)-Cl(4) bond lengths are 2.94 Å. In the third Ce site, Ce(3) is bonded in a 9-coordinate geometry to three equivalent Cl(1) and six equivalent Cl(3) atoms. All Ce(3)-Cl(1) bond lengths are 3.00 Å. All Ce(3)-Cl(3) bond lengths are 2.92 Å. There are four inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a trigonal non-coplanar geometry to one Ce(3) and two equivalent Ce(1) atoms. In the second Cl site, Cl(2) is bonded to one Na(1), one Na(2), one Ce(1), and one Ce(2) atom to form ClNa2Ce2 tetrahedra that share corners with three equivalent Cl(4)Na3Ce2 square pyramids, corners with seven equivalent Cl(2)Na2Ce2 tetrahedra, edges with three equivalent Cl(4)Na3Ce2 square pyramids, and edges with two equivalent Cl(2)Na2Ce2 tetrahedra. In the third Cl site, Cl(3) is bonded in a trigonal non-coplanar geometry to one Ce(1), one Ce(2), and one Ce(3) atom. In the fourth Cl site, Cl(4) is bonded to one Na(1), two equivalent Na(2), and two equivalent Ce(2) atoms to form distorted ClNa3Ce2 square pyramids that share corners with two equivalent Cl(4)Na3Ce2 square pyramids, corners with six equivalent Cl(2)Na2Ce2 tetrahedra, edges with four equivalent Cl(4)Na3Ce2 square pyramids, and edges with six equivalent Cl(2)Na2Ce2 tetrahedra.