CeMg crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to four equivalent Mg(2), two equivalent Ce(2), and six equivalent Ce(1) atoms to form MgCe8Mg4 cuboctahedra that share edges with four equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with six equivalent Mg(1)Ce8Mg4 cuboctahedra, faces with two equivalent Mg(1)Ce8Mg4 cuboctahedra, and faces with four equivalent Ce(2)Ce4Mg8 cuboctahedra. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), three equivalent Ce(2), and four equivalent Ce(1) atoms. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 12-coordinate geometry to three equivalent Mg(1), four equivalent Mg(2), two equivalent Ce(2), and three equivalent Ce(1) atoms. In the second Ce site, Ce(2) is bonded to two equivalent Mg(1), six equivalent Mg(2), and four equivalent Ce(1) atoms to form CeCe4Mg8 cuboctahedra that share edges with four equivalent Mg(1)Ce8Mg4 cuboctahedra, edges with six equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, and faces with four equivalent Mg(1)Ce8Mg4 cuboctahedra.
CeMg crystallizes in the orthorhombic Amm2 space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to four equivalent Mg(2), two equivalent Ce(2), and six equivalent Ce(1) atoms to form MgCe8Mg4 cuboctahedra that share edges with four equivalent Ce(2)Ce4Mg8 cuboctahedra, edges with six equivalent Mg(1)Ce8Mg4 cuboctahedra, faces with two equivalent Mg(1)Ce8Mg4 cuboctahedra, and faces with four equivalent Ce(2)Ce4Mg8 cuboctahedra. All Mg(1)-Mg(2) bond lengths are 3.24 Å. Both Mg(1)-Ce(2) bond lengths are 3.34 Å. There are a spread of Mg(1)-Ce(1) bond distances ranging from 3.31-3.53 Å. In the second Mg site, Mg(2) is bonded in a 12-coordinate geometry to two equivalent Mg(1), three equivalent Mg(2), three equivalent Ce(2), and four equivalent Ce(1) atoms. There is one shorter (3.13 Å) and two longer (3.51 Å) Mg(2)-Mg(2) bond lengths. There are a spread of Mg(2)-Ce(2) bond distances ranging from 3.32-3.48 Å. There are two shorter (3.38 Å) and two longer (3.45 Å) Mg(2)-Ce(1) bond lengths. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded in a 12-coordinate geometry to three equivalent Mg(1), four equivalent Mg(2), two equivalent Ce(2), and three equivalent Ce(1) atoms. Both Ce(1)-Ce(2) bond lengths are 3.17 Å. There is one shorter (2.70 Å) and two longer (3.74 Å) Ce(1)-Ce(1) bond lengths. In the second Ce site, Ce(2) is bonded to two equivalent Mg(1), six equivalent Mg(2), and four equivalent Ce(1) atoms to form CeCe4Mg8 cuboctahedra that share edges with four equivalent Mg(1)Ce8Mg4 cuboctahedra, edges with six equivalent Ce(2)Ce4Mg8 cuboctahedra, faces with two equivalent Ce(2)Ce4Mg8 cuboctahedra, and faces with four equivalent Mg(1)Ce8Mg4 cuboctahedra.