Mg(BiO2)4 crystallizes in the trigonal R-3m space group. Mg(1) is bonded to six equivalent O(1) atoms to form MgO6 octahedra that share corners with six equivalent Bi(2)O6 octahedra and edges with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form BiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Bi(2)O6 octahedra, and edges with four equivalent Bi(1)O6 octahedra. In the second Bi site, Bi(2) is bonded to six equivalent O(1) atoms to form BiO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra and edges with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to three equivalent Bi(1) atoms.
Mg(BiO2)4 crystallizes in the trigonal R-3m space group. Mg(1) is bonded to six equivalent O(1) atoms to form MgO6 octahedra that share corners with six equivalent Bi(2)O6 octahedra and edges with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. All Mg(1)-O(1) bond lengths are 2.26 Å. There are two inequivalent Bi sites. In the first Bi site, Bi(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form BiO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Bi(2)O6 octahedra, and edges with four equivalent Bi(1)O6 octahedra. Both Bi(1)-O(2) bond lengths are 2.30 Å. All Bi(1)-O(1) bond lengths are 2.31 Å. In the second Bi site, Bi(2) is bonded to six equivalent O(1) atoms to form BiO6 octahedra that share corners with six equivalent Mg(1)O6 octahedra and edges with six equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles are 5°. All Bi(2)-O(1) bond lengths are 2.53 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Bi(2), and two equivalent Bi(1) atoms. In the second O site, O(2) is bonded in a trigonal non-coplanar geometry to three equivalent Bi(1) atoms.