MgCe3 is beta-derived structured and crystallizes in the orthorhombic Imm2 space group. Mg(1) is bonded to two equivalent Mg(1), four equivalent Ce(1), and six equivalent Ce(2) atoms to form MgCe10Mg2 cuboctahedra that share corners with four equivalent Ce(1)Ce8Mg4 cuboctahedra, corners with fourteen equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with two equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with four equivalent Ce(1)Ce8Mg4 cuboctahedra, edges with twelve equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with two equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with six equivalent Ce(1)Ce8Mg4 cuboctahedra, and faces with twelve equivalent Ce(2)Ce9Mg3 cuboctahedra. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to four equivalent Mg(1), two equivalent Ce(1), and six equivalent Ce(2) atoms to form CeCe8Mg4 cuboctahedra that share corners with four equivalent Mg(1)Ce10Mg2 cuboctahedra, corners with fourteen equivalent Ce(1)Ce8Mg4 cuboctahedra, edges with two equivalent Ce(1)Ce8Mg4 cuboctahedra, edges with four equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with twelve equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with two equivalent Ce(1)Ce8Mg4 cuboctahedra, faces with six equivalent Mg(1)Ce10Mg2 cuboctahedra, and faces with twelve equivalent Ce(2)Ce9Mg3 cuboctahedra. In the second Ce site, Ce(2) is bonded to three equivalent Mg(1), three equivalent Ce(1), and six equivalent Ce(2) atoms to form CeCe9Mg3 cuboctahedra that share corners with eighteen equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with six equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with six equivalent Ce(1)Ce8Mg4 cuboctahedra, edges with six equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with six equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with six equivalent Ce(1)Ce8Mg4 cuboctahedra, and faces with eight equivalent Ce(2)Ce9Mg3 cuboctahedra.
MgCe3 is beta-derived structured and crystallizes in the orthorhombic Imm2 space group. Mg(1) is bonded to two equivalent Mg(1), four equivalent Ce(1), and six equivalent Ce(2) atoms to form MgCe10Mg2 cuboctahedra that share corners with four equivalent Ce(1)Ce8Mg4 cuboctahedra, corners with fourteen equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with two equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with four equivalent Ce(1)Ce8Mg4 cuboctahedra, edges with twelve equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with two equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with six equivalent Ce(1)Ce8Mg4 cuboctahedra, and faces with twelve equivalent Ce(2)Ce9Mg3 cuboctahedra. Both Mg(1)-Mg(1) bond lengths are 3.26 Å. There are two shorter (3.34 Å) and two longer (3.52 Å) Mg(1)-Ce(1) bond lengths. There are four shorter (3.35 Å) and two longer (3.42 Å) Mg(1)-Ce(2) bond lengths. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to four equivalent Mg(1), two equivalent Ce(1), and six equivalent Ce(2) atoms to form CeCe8Mg4 cuboctahedra that share corners with four equivalent Mg(1)Ce10Mg2 cuboctahedra, corners with fourteen equivalent Ce(1)Ce8Mg4 cuboctahedra, edges with two equivalent Ce(1)Ce8Mg4 cuboctahedra, edges with four equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with twelve equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with two equivalent Ce(1)Ce8Mg4 cuboctahedra, faces with six equivalent Mg(1)Ce10Mg2 cuboctahedra, and faces with twelve equivalent Ce(2)Ce9Mg3 cuboctahedra. Both Ce(1)-Ce(1) bond lengths are 3.26 Å. There are four shorter (3.32 Å) and two longer (3.48 Å) Ce(1)-Ce(2) bond lengths. In the second Ce site, Ce(2) is bonded to three equivalent Mg(1), three equivalent Ce(1), and six equivalent Ce(2) atoms to form CeCe9Mg3 cuboctahedra that share corners with eighteen equivalent Ce(2)Ce9Mg3 cuboctahedra, edges with six equivalent Mg(1)Ce10Mg2 cuboctahedra, edges with six equivalent Ce(1)Ce8Mg4 cuboctahedra, edges with six equivalent Ce(2)Ce9Mg3 cuboctahedra, faces with six equivalent Mg(1)Ce10Mg2 cuboctahedra, faces with six equivalent Ce(1)Ce8Mg4 cuboctahedra, and faces with eight equivalent Ce(2)Ce9Mg3 cuboctahedra. There are two shorter (3.26 Å) and four longer (3.43 Å) Ce(2)-Ce(2) bond lengths.