Li2Fe3NiO8 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(2) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with six equivalent Fe(2)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Fe(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(3) 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 Fe(2)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-12°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. In the second Fe site, Fe(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 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 Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-10°. Ni(1) is bonded to two equivalent O(3) 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 Fe(2)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-12°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Fe(1), one Fe(2), and one Ni(1) atom to form a mixture of edge and corner-sharing OLi2Fe2Ni square pyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(1), one Fe(2), and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(2), two equivalent Fe(1), and one Ni(1) atom.
Li2Fe3NiO8 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(2) and four equivalent O(1) atoms to form LiO6 octahedra that share corners with six equivalent Fe(2)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Ni(1)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-10°. Both Li(1)-O(2) bond lengths are 2.17 Å. All Li(1)-O(1) bond lengths are 2.16 Å. In the second Li site, Li(2) is bonded to two equivalent O(3) 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 Fe(2)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-12°. Both Li(2)-O(3) bond lengths are 2.16 Å. All Li(2)-O(1) bond lengths are 2.12 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Li(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. Both Fe(1)-O(1) bond lengths are 1.89 Å. Both Fe(1)-O(2) bond lengths are 1.91 Å. Both Fe(1)-O(3) bond lengths are 1.89 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form FeO6 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 Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-10°. Both Fe(2)-O(2) bond lengths are 1.93 Å. All Fe(2)-O(1) bond lengths are 1.92 Å. Ni(1) is bonded to two equivalent O(3) 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 Fe(2)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 11-12°. Both Ni(1)-O(3) bond lengths are 1.94 Å. All Ni(1)-O(1) bond lengths are 1.97 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(2), one Fe(1), one Fe(2), and one Ni(1) atom to form a mixture of edge and corner-sharing OLi2Fe2Ni square pyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(1), one Fe(2), and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(2), two equivalent Fe(1), and one Ni(1) atom.