SmMg2Bi2 crystallizes in the trigonal P-3m1 space group. Mg(1) is bonded to four equivalent Bi(1) atoms to form MgBi4 tetrahedra that share corners with six equivalent Sm(1)Bi6 octahedra, corners with six equivalent Mg(1)Bi4 tetrahedra, edges with three equivalent Sm(1)Bi6 octahedra, and edges with three equivalent Mg(1)Bi4 tetrahedra. The corner-sharing octahedral tilt angles range from 15-58°. Sm(1) is bonded to six equivalent Bi(1) atoms to form SmBi6 octahedra that share corners with twelve equivalent Mg(1)Bi4 tetrahedra, edges with six equivalent Sm(1)Bi6 octahedra, and edges with six equivalent Mg(1)Bi4 tetrahedra. Bi(1) is bonded to four equivalent Mg(1) and three equivalent Sm(1) atoms to form a mixture of distorted corner and edge-sharing BiSm3Mg4 pentagonal bipyramids.
SmMg2Bi2 crystallizes in the trigonal P-3m1 space group. Mg(1) is bonded to four equivalent Bi(1) atoms to form MgBi4 tetrahedra that share corners with six equivalent Sm(1)Bi6 octahedra, corners with six equivalent Mg(1)Bi4 tetrahedra, edges with three equivalent Sm(1)Bi6 octahedra, and edges with three equivalent Mg(1)Bi4 tetrahedra. The corner-sharing octahedral tilt angles range from 15-58°. There are three shorter (2.94 Å) and one longer (2.98 Å) Mg(1)-Bi(1) bond length. Sm(1) is bonded to six equivalent Bi(1) atoms to form SmBi6 octahedra that share corners with twelve equivalent Mg(1)Bi4 tetrahedra, edges with six equivalent Sm(1)Bi6 octahedra, and edges with six equivalent Mg(1)Bi4 tetrahedra. All Sm(1)-Bi(1) bond lengths are 3.33 Å. Bi(1) is bonded to four equivalent Mg(1) and three equivalent Sm(1) atoms to form a mixture of distorted corner and edge-sharing BiSm3Mg4 pentagonal bipyramids.