Ba(MgBi)2 crystallizes in the trigonal P-3m1 space group. Ba(1) is bonded to six equivalent Bi(1) atoms to form BaBi6 octahedra that share corners with twelve equivalent Mg(1)Bi4 tetrahedra, edges with six equivalent Ba(1)Bi6 octahedra, and edges with six equivalent Mg(1)Bi4 tetrahedra. Mg(1) is bonded to four equivalent Bi(1) atoms to form MgBi4 tetrahedra that share corners with six equivalent Ba(1)Bi6 octahedra, corners with six equivalent Mg(1)Bi4 tetrahedra, edges with three equivalent Ba(1)Bi6 octahedra, and edges with three equivalent Mg(1)Bi4 tetrahedra. The corner-sharing octahedral tilt angles range from 20-52°. Bi(1) is bonded to three equivalent Ba(1) and four equivalent Mg(1) atoms to form a mixture of distorted corner and edge-sharing BiBa3Mg4 pentagonal bipyramids.
Ba(MgBi)2 crystallizes in the trigonal P-3m1 space group. Ba(1) is bonded to six equivalent Bi(1) atoms to form BaBi6 octahedra that share corners with twelve equivalent Mg(1)Bi4 tetrahedra, edges with six equivalent Ba(1)Bi6 octahedra, and edges with six equivalent Mg(1)Bi4 tetrahedra. All Ba(1)-Bi(1) bond lengths are 3.59 Å. Mg(1) is bonded to four equivalent Bi(1) atoms to form MgBi4 tetrahedra that share corners with six equivalent Ba(1)Bi6 octahedra, corners with six equivalent Mg(1)Bi4 tetrahedra, edges with three equivalent Ba(1)Bi6 octahedra, and edges with three equivalent Mg(1)Bi4 tetrahedra. The corner-sharing octahedral tilt angles range from 20-52°. There is one shorter (2.97 Å) and three longer (2.98 Å) Mg(1)-Bi(1) bond lengths. Bi(1) is bonded to three equivalent Ba(1) and four equivalent Mg(1) atoms to form a mixture of distorted corner and edge-sharing BiBa3Mg4 pentagonal bipyramids.