Li2Mn3NiO8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with six equivalent Mn(2)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-10°. In the second Li site, Li(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-13°. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. In the second Mn site, Mn(2) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-10°. Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with six equivalent Li(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-13°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Mn(1), one Mn(2), and one Ni(1) atom to form a mixture of corner and edge-sharing OLi2Mn2Ni square pyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(2), two equivalent Mn(1), and one Ni(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(1), one Mn(2), and two equivalent Mn(1) atoms.
Li2Mn3NiO8 crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with six equivalent Mn(2)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-10°. Both Li(1)-O(3) bond lengths are 2.22 Å. All Li(1)-O(1) bond lengths are 2.22 Å. In the second Li site, Li(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-13°. Both Li(2)-O(2) bond lengths are 2.15 Å. All Li(2)-O(1) bond lengths are 2.11 Å. There are two inequivalent Mn sites. In the first Mn site, Mn(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MnO6 octahedra that share edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Mn(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. Both Mn(1)-O(1) bond lengths are 1.93 Å. Both Mn(1)-O(2) bond lengths are 1.92 Å. Both Mn(1)-O(3) bond lengths are 1.96 Å. In the second Mn site, Mn(2) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form MnO6 octahedra that share corners with six equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-10°. Both Mn(2)-O(3) bond lengths are 1.97 Å. All Mn(2)-O(1) bond lengths are 1.95 Å. Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with six equivalent Li(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Mn(2)O6 octahedra, and edges with four equivalent Mn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-13°. Both Ni(1)-O(2) bond lengths are 2.06 Å. All Ni(1)-O(1) bond lengths are 2.07 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Mn(1), one Mn(2), and one Ni(1) atom to form a mixture of corner and edge-sharing OLi2Mn2Ni square pyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(2), two equivalent Mn(1), and one Ni(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(1), one Mn(2), and two equivalent Mn(1) atoms.