Li2Fe3CoO8 crystallizes in the monoclinic C2/m space group. Li(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share corners with six equivalent Fe(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-13°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form FeO6 octahedra that share edges with two equivalent Co(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with six equivalent Li(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-13°. Co(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CoO6 octahedra that share edges with two equivalent Fe(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Li(1), one Fe(1), one Fe(2), and one Co(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), two equivalent Fe(2), and one Co(1) atom to form OLi2Fe2Co square pyramids that share corners with two equivalent O(3)Li2Fe3 square pyramids, corners with three equivalent O(2)Li2Fe2Co square pyramids,  an edgeedge with one O(2)Li2Fe2Co square pyramid, and edges with three equivalent O(3)Li2Fe3 square pyramids. In the third O site, O(3) is bonded to two equivalent Li(1), one Fe(1), and two equivalent Fe(2) atoms to form OLi2Fe3 square pyramids that share corners with two equivalent O(2)Li2Fe2Co square pyramids, corners with three equivalent O(3)Li2Fe3 square pyramids,  an edgeedge with one O(3)Li2Fe3 square pyramid, and edges with three equivalent O(2)Li2Fe2Co square pyramids.
Li2Fe3CoO8 crystallizes in the monoclinic C2/m space group. Li(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form LiO6 octahedra that share corners with six equivalent Fe(2)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-13°. Both Li(1)-O(1) bond lengths are 2.16 Å. Both Li(1)-O(2) bond lengths are 2.19 Å. Both Li(1)-O(3) bond lengths are 2.19 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form FeO6 octahedra that share edges with two equivalent Co(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. Both Fe(1)-O(3) bond lengths are 1.94 Å. All Fe(1)-O(1) bond lengths are 2.00 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with six equivalent Li(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Co(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-13°. Both Fe(2)-O(1) bond lengths are 2.05 Å. Both Fe(2)-O(2) bond lengths are 2.03 Å. Both Fe(2)-O(3) bond lengths are 2.06 Å. Co(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form CoO6 octahedra that share edges with two equivalent Fe(1)O6 octahedra, edges with four equivalent Li(1)O6 octahedra, and edges with four equivalent Fe(2)O6 octahedra. Both Co(1)-O(2) bond lengths are 1.91 Å. All Co(1)-O(1) bond lengths are 1.90 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Li(1), one Fe(1), one Fe(2), and one Co(1) atom. In the second O site, O(2) is bonded to two equivalent Li(1), two equivalent Fe(2), and one Co(1) atom to form OLi2Fe2Co square pyramids that share corners with two equivalent O(3)Li2Fe3 square pyramids, corners with three equivalent O(2)Li2Fe2Co square pyramids,  an edgeedge with one O(2)Li2Fe2Co square pyramid, and edges with three equivalent O(3)Li2Fe3 square pyramids. In the third O site, O(3) is bonded to two equivalent Li(1), one Fe(1), and two equivalent Fe(2) atoms to form OLi2Fe3 square pyramids that share corners with two equivalent O(2)Li2Fe2Co square pyramids, corners with three equivalent O(3)Li2Fe3 square pyramids,  an edgeedge with one O(3)Li2Fe3 square pyramid, and edges with three equivalent O(2)Li2Fe2Co square pyramids.