SmMg2Sb2 crystallizes in the trigonal P-3m1 space group. Mg(1) is bonded to four equivalent Sb(1) atoms to form MgSb4 tetrahedra that share corners with six equivalent Sm(1)Sb6 octahedra, corners with six equivalent Mg(1)Sb4 tetrahedra, edges with three equivalent Sm(1)Sb6 octahedra, and edges with three equivalent Mg(1)Sb4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-57°. Sm(1) is bonded to six equivalent Sb(1) atoms to form SmSb6 octahedra that share corners with twelve equivalent Mg(1)Sb4 tetrahedra, edges with six equivalent Sm(1)Sb6 octahedra, and edges with six equivalent Mg(1)Sb4 tetrahedra. Sb(1) is bonded to four equivalent Mg(1) and three equivalent Sm(1) atoms to form a mixture of distorted corner and edge-sharing SbSm3Mg4 pentagonal bipyramids.
SmMg2Sb2 crystallizes in the trigonal P-3m1 space group. Mg(1) is bonded to four equivalent Sb(1) atoms to form MgSb4 tetrahedra that share corners with six equivalent Sm(1)Sb6 octahedra, corners with six equivalent Mg(1)Sb4 tetrahedra, edges with three equivalent Sm(1)Sb6 octahedra, and edges with three equivalent Mg(1)Sb4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-57°. There are three shorter (2.84 Å) and one longer (2.91 Å) Mg(1)-Sb(1) bond length. Sm(1) is bonded to six equivalent Sb(1) atoms to form SmSb6 octahedra that share corners with twelve equivalent Mg(1)Sb4 tetrahedra, edges with six equivalent Sm(1)Sb6 octahedra, and edges with six equivalent Mg(1)Sb4 tetrahedra. All Sm(1)-Sb(1) bond lengths are 3.25 Å. Sb(1) is bonded to four equivalent Mg(1) and three equivalent Sm(1) atoms to form a mixture of distorted corner and edge-sharing SbSm3Mg4 pentagonal bipyramids.