MgCe5 is beta-derived structured and crystallizes in the monoclinic Cm space group. Mg(1) is bonded to two equivalent Mg(1), one Ce(4), two equivalent Ce(1), two equivalent Ce(3), two equivalent Ce(5), and three equivalent Ce(2) atoms to form MgCe10Mg2 cuboctahedra that share corners with six equivalent Mg(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(3)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with two equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with three equivalent Ce(3)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with four equivalent Ce(4)Ce11Mg cuboctahedra, edges with six equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with two equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with four equivalent Ce(4)Ce11Mg cuboctahedra, and faces with five equivalent Ce(2)Ce9Mg3 cuboctahedra. There are five inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent Mg(1), one Ce(3), two equivalent Ce(1), two equivalent Ce(2), two equivalent Ce(4), and three equivalent Ce(5) atoms to form distorted CeCe10Mg2 cuboctahedra that share corners with six equivalent Ce(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(4)Ce11Mg cuboctahedra, corners with six equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with two equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(4)Ce11Mg cuboctahedra, edges with three equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with four equivalent Ce(3)Ce10Mg2 cuboctahedra, edges with six equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with two equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with three equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(4)Ce11Mg cuboctahedra, faces with three equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with four equivalent Ce(3)Ce10Mg2 cuboctahedra, and faces with five equivalent Ce(5)Ce10Mg2 cuboctahedra. In the second Ce site, Ce(2) is bonded to three equivalent Mg(1), one Ce(5), two equivalent Ce(1), two equivalent Ce(2), two equivalent Ce(3), and two equivalent Ce(4) atoms to form distorted CeCe9Mg3 cuboctahedra that share corners with six equivalent Ce(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(4)Ce11Mg cuboctahedra, corners with six equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with two equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(4)Ce11Mg cuboctahedra, edges with four equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with six equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with two equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with three equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(4)Ce11Mg cuboctahedra, faces with four equivalent Ce(5)Ce10Mg2 cuboctahedra, and faces with five equivalent Mg(1)Ce10Mg2 cuboctahedra. In the third Ce site, Ce(3) is bonded to two equivalent Mg(1), one Ce(1), two equivalent Ce(2), two equivalent Ce(3), two equivalent Ce(5), and three equivalent Ce(4) atoms to form distorted CeCe10Mg2 cuboctahedra that share corners with six equivalent Mg(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(3)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with two equivalent Ce(4)Ce11Mg cuboctahedra, edges with three equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with four equivalent Ce(1)Ce10Mg2 cuboctahedra, edges with six equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with two equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with three equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with four equivalent Ce(1)Ce10Mg2 cuboctahedra, and faces with five equivalent Ce(4)Ce11Mg cuboctahedra. In the fourth Ce site, Ce(4) is bonded to one Mg(1), two equivalent Ce(1), two equivalent Ce(2), two equivalent Ce(4), two equivalent Ce(5), and three equivalent Ce(3) atoms to form distorted CeCe11Mg cuboctahedra that share corners with six equivalent Ce(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(4)Ce11Mg cuboctahedra, corners with six equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with two equivalent Ce(3)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with four equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with six equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with two equivalent Ce(4)Ce11Mg cuboctahedra, faces with three equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with four equivalent Mg(1)Ce10Mg2 cuboctahedra, and faces with five equivalent Ce(3)Ce10Mg2 cuboctahedra. In the fifth Ce site, Ce(5) is bonded to two equivalent Mg(1), one Ce(2), two equivalent Ce(3), two equivalent Ce(4), two equivalent Ce(5), and three equivalent Ce(1) atoms to form distorted CeCe10Mg2 cuboctahedra that share corners with six equivalent Mg(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(3)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with two equivalent Ce(1)Ce10Mg2 cuboctahedra, edges with three equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(3)Ce10Mg2 cuboctahedra, edges with four equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with six equivalent Ce(4)Ce11Mg cuboctahedra, faces with two equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with three equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(4)Ce11Mg cuboctahedra, faces with four equivalent Ce(2)Ce9Mg3 cuboctahedra, and faces with five equivalent Ce(1)Ce10Mg2 cuboctahedra.
MgCe5 is beta-derived structured and crystallizes in the monoclinic Cm space group. Mg(1) is bonded to two equivalent Mg(1), one Ce(4), two equivalent Ce(1), two equivalent Ce(3), two equivalent Ce(5), and three equivalent Ce(2) atoms to form MgCe10Mg2 cuboctahedra that share corners with six equivalent Mg(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(3)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with two equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with three equivalent Ce(3)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with four equivalent Ce(4)Ce11Mg cuboctahedra, edges with six equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with two equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with four equivalent Ce(4)Ce11Mg cuboctahedra, and faces with five equivalent Ce(2)Ce9Mg3 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 3.24 Å. The Mg(1)-Ce(4) bond length is 3.38 Å. Both Mg(1)-Ce(1) bond lengths are 3.32 Å. Both Mg(1)-Ce(3) bond lengths are 3.36 Å. Both Mg(1)-Ce(5) bond lengths are 3.49 Å. There are two shorter (3.38 Å) and one longer (3.46 Å) Mg(1)-Ce(2) bond length. There are five inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to two equivalent Mg(1), one Ce(3), two equivalent Ce(1), two equivalent Ce(2), two equivalent Ce(4), and three equivalent Ce(5) atoms to form distorted CeCe10Mg2 cuboctahedra that share corners with six equivalent Ce(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(4)Ce11Mg cuboctahedra, corners with six equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with two equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(4)Ce11Mg cuboctahedra, edges with three equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with four equivalent Ce(3)Ce10Mg2 cuboctahedra, edges with six equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with two equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with three equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(4)Ce11Mg cuboctahedra, faces with three equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with four equivalent Ce(3)Ce10Mg2 cuboctahedra, and faces with five equivalent Ce(5)Ce10Mg2 cuboctahedra. The Ce(1)-Ce(3) bond length is 3.49 Å. Both Ce(1)-Ce(1) bond lengths are 3.24 Å. Both Ce(1)-Ce(2) bond lengths are 3.15 Å. Both Ce(1)-Ce(4) bond lengths are 3.21 Å. There are two shorter (3.43 Å) and one longer (3.55 Å) Ce(1)-Ce(5) bond length. In the second Ce site, Ce(2) is bonded to three equivalent Mg(1), one Ce(5), two equivalent Ce(1), two equivalent Ce(2), two equivalent Ce(3), and two equivalent Ce(4) atoms to form distorted CeCe9Mg3 cuboctahedra that share corners with six equivalent Ce(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(4)Ce11Mg cuboctahedra, corners with six equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with two equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(4)Ce11Mg cuboctahedra, edges with four equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with six equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with two equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with three equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(4)Ce11Mg cuboctahedra, faces with four equivalent Ce(5)Ce10Mg2 cuboctahedra, and faces with five equivalent Mg(1)Ce10Mg2 cuboctahedra. The Ce(2)-Ce(5) bond length is 3.57 Å. Both Ce(2)-Ce(2) bond lengths are 3.24 Å. Both Ce(2)-Ce(3) bond lengths are 3.48 Å. Both Ce(2)-Ce(4) bond lengths are 3.38 Å. In the third Ce site, Ce(3) is bonded to two equivalent Mg(1), one Ce(1), two equivalent Ce(2), two equivalent Ce(3), two equivalent Ce(5), and three equivalent Ce(4) atoms to form distorted CeCe10Mg2 cuboctahedra that share corners with six equivalent Mg(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(3)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with two equivalent Ce(4)Ce11Mg cuboctahedra, edges with three equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with four equivalent Ce(1)Ce10Mg2 cuboctahedra, edges with six equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with two equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with three equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with four equivalent Ce(1)Ce10Mg2 cuboctahedra, and faces with five equivalent Ce(4)Ce11Mg cuboctahedra. Both Ce(3)-Ce(3) bond lengths are 3.24 Å. Both Ce(3)-Ce(5) bond lengths are 2.89 Å. There are two shorter (3.30 Å) and one longer (3.54 Å) Ce(3)-Ce(4) bond length. In the fourth Ce site, Ce(4) is bonded to one Mg(1), two equivalent Ce(1), two equivalent Ce(2), two equivalent Ce(4), two equivalent Ce(5), and three equivalent Ce(3) atoms to form distorted CeCe11Mg cuboctahedra that share corners with six equivalent Ce(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(4)Ce11Mg cuboctahedra, corners with six equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with two equivalent Ce(3)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with four equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with six equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with two equivalent Ce(4)Ce11Mg cuboctahedra, faces with three equivalent Ce(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with four equivalent Mg(1)Ce10Mg2 cuboctahedra, and faces with five equivalent Ce(3)Ce10Mg2 cuboctahedra. Both Ce(4)-Ce(4) bond lengths are 3.24 Å. Both Ce(4)-Ce(5) bond lengths are 3.43 Å. In the fifth Ce site, Ce(5) is bonded to two equivalent Mg(1), one Ce(2), two equivalent Ce(3), two equivalent Ce(4), two equivalent Ce(5), and three equivalent Ce(1) atoms to form distorted CeCe10Mg2 cuboctahedra that share corners with six equivalent Mg(1)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(3)Ce10Mg2 cuboctahedra, corners with six equivalent Ce(5)Ce10Mg2 cuboctahedra, edges with two equivalent Ce(1)Ce10Mg2 cuboctahedra, edges with three equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with three equivalent Ce(3)Ce10Mg2 cuboctahedra, edges with four equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with six equivalent Ce(4)Ce11Mg cuboctahedra, faces with two equivalent Ce(5)Ce10Mg2 cuboctahedra, faces with three equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(3)Ce10Mg2 cuboctahedra, faces with three equivalent Ce(4)Ce11Mg cuboctahedra, faces with four equivalent Ce(2)Ce9Mg3 cuboctahedra, and faces with five equivalent Ce(1)Ce10Mg2 cuboctahedra. Both Ce(5)-Ce(5) bond lengths are 3.24 Å.