MnNi7O8 is Caswellsilverite-like structured and crystallizes in the cubic Fm-3m space group. Mn(1) is bonded to six equivalent O(2) atoms to form MnO6 octahedra that share corners with six equivalent Ni(2)O6 octahedra and edges with twelve equivalent Ni(1)O6 octahedra. The corner-sharing octahedra are not tilted. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NiO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with eight equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. In the second Ni site, Ni(2) is bonded to six equivalent O(2) atoms to form NiO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra and edges with twelve equivalent Ni(1)O6 octahedra. The corner-sharing octahedra are not tilted. There are three inequivalent O sites. In the first O site, O(1) is bonded to six equivalent Ni(1) atoms to form ONi6 octahedra that share corners with six equivalent O(1)Ni6 octahedra and edges with twelve equivalent O(2)MnNi5 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to one Mn(1), one Ni(2), and four equivalent Ni(1) atoms to form OMnNi5 octahedra that share corners with six equivalent O(2)MnNi5 octahedra, edges with four equivalent O(1)Ni6 octahedra, and edges with eight equivalent O(2)MnNi5 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(2) is bonded to one Mn(1), one Ni(2), and four equivalent Ni(1) atoms to form OMnNi5 octahedra that share corners with six equivalent O(2)MnNi5 octahedra, edges with four equivalent O(1)Ni6 octahedra, and edges with eight equivalent O(2)MnNi5 octahedra. The corner-sharing octahedra are not tilted.
MnNi7O8 is Caswellsilverite-like structured and crystallizes in the cubic Fm-3m space group. Mn(1) is bonded to six equivalent O(2) atoms to form MnO6 octahedra that share corners with six equivalent Ni(2)O6 octahedra and edges with twelve equivalent Ni(1)O6 octahedra. The corner-sharing octahedra are not tilted. All Mn(1)-O(2) bond lengths are 2.18 Å. There are two inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form NiO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Ni(2)O6 octahedra, and edges with eight equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-2°. Both Ni(1)-O(1) bond lengths are 2.13 Å. All Ni(1)-O(2) bond lengths are 2.13 Å. In the second Ni site, Ni(2) is bonded to six equivalent O(2) atoms to form NiO6 octahedra that share corners with six equivalent Mn(1)O6 octahedra and edges with twelve equivalent Ni(1)O6 octahedra. The corner-sharing octahedra are not tilted. All Ni(2)-O(2) bond lengths are 2.09 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to six equivalent Ni(1) atoms to form ONi6 octahedra that share corners with six equivalent O(1)Ni6 octahedra and edges with twelve equivalent O(2)MnNi5 octahedra. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to one Mn(1), one Ni(2), and four equivalent Ni(1) atoms to form OMnNi5 octahedra that share corners with six equivalent O(2)MnNi5 octahedra, edges with four equivalent O(1)Ni6 octahedra, and edges with eight equivalent O(2)MnNi5 octahedra. The corner-sharing octahedra are not tilted. In the third O site, O(2) is bonded to one Mn(1), one Ni(2), and four equivalent Ni(1) atoms to form OMnNi5 octahedra that share corners with six equivalent O(2)MnNi5 octahedra, edges with four equivalent O(1)Ni6 octahedra, and edges with eight equivalent O(2)MnNi5 octahedra. The corner-sharing octahedra are not tilted. The O(2)-Mn(1) bond length is 2.18 Å. The O(2)-Ni(2) bond length is 2.09 Å. All O(2)-Ni(1) bond lengths are 2.13 Å.