MgRe2NiO8 crystallizes in the trigonal P-3 space group. Mg(1) is bonded to six equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Re(1)O4 tetrahedra and faces with two equivalent Ni(1)O6 octahedra. Re(1) is bonded to one O(1) and three equivalent O(2) atoms to form ReO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra and corners with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-55°. Ni(1) is bonded to six equivalent O(2) atoms to form NiO6 octahedra that share corners with six equivalent Re(1)O4 tetrahedra and faces with two equivalent Mg(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Re(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Re(1), and one Ni(1) atom.
MgRe2NiO8 crystallizes in the trigonal P-3 space group. Mg(1) is bonded to six equivalent O(2) atoms to form MgO6 octahedra that share corners with six equivalent Re(1)O4 tetrahedra and faces with two equivalent Ni(1)O6 octahedra. All Mg(1)-O(2) bond lengths are 2.12 Å. Re(1) is bonded to one O(1) and three equivalent O(2) atoms to form ReO4 tetrahedra that share corners with three equivalent Mg(1)O6 octahedra and corners with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-55°. The Re(1)-O(1) bond length is 1.73 Å. All Re(1)-O(2) bond lengths are 1.81 Å. Ni(1) is bonded to six equivalent O(2) atoms to form NiO6 octahedra that share corners with six equivalent Re(1)O4 tetrahedra and faces with two equivalent Mg(1)O6 octahedra. All Ni(1)-O(2) bond lengths are 2.11 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Re(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Mg(1), one Re(1), and one Ni(1) atom.