Li3FeNi3O8 crystallizes in the trigonal R-3m space group. Li(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form LiO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-10°. Fe(1) is bonded to six equivalent O(2) atoms to form FeO6 octahedra that share edges with six equivalent Li(1)O6 octahedra and edges with six equivalent Ni(1)O6 octahedra. 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 Li(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-10°. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Li(1) and three equivalent Ni(1) atoms to form OLi3Ni3 octahedra that share corners with six equivalent O(1)Li3Ni3 octahedra and edges with twelve equivalent O(2)Li2FeNi2 square pyramids. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Li(1), one Fe(1), and two equivalent Ni(1) atoms to form OLi2FeNi2 square pyramids that share corners with nine equivalent O(2)Li2FeNi2 square pyramids, edges with four equivalent O(1)Li3Ni3 octahedra, and edges with four equivalent O(2)Li2FeNi2 square pyramids.
Li3FeNi3O8 crystallizes in the trigonal R-3m space group. Li(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form LiO6 octahedra that share corners with six equivalent Ni(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-10°. Both Li(1)-O(1) bond lengths are 2.17 Å. All Li(1)-O(2) bond lengths are 2.12 Å. Fe(1) is bonded to six equivalent O(2) atoms to form FeO6 octahedra that share edges with six equivalent Li(1)O6 octahedra and edges with six equivalent Ni(1)O6 octahedra. All Fe(1)-O(2) bond lengths are 1.88 Å. 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 Li(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-10°. Both Ni(1)-O(1) bond lengths are 1.98 Å. All Ni(1)-O(2) bond lengths are 2.04 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Li(1) and three equivalent Ni(1) atoms to form OLi3Ni3 octahedra that share corners with six equivalent O(1)Li3Ni3 octahedra and edges with twelve equivalent O(2)Li2FeNi2 square pyramids. The corner-sharing octahedra are not tilted. In the second O site, O(2) is bonded to two equivalent Li(1), one Fe(1), and two equivalent Ni(1) atoms to form OLi2FeNi2 square pyramids that share corners with nine equivalent O(2)Li2FeNi2 square pyramids, edges with four equivalent O(1)Li3Ni3 octahedra, and edges with four equivalent O(2)Li2FeNi2 square pyramids.