Li2Fe3CuO8 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) 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 Fe(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-12°. In the second Li site, Li(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form LiO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-11°. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form FeO6 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, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-11°. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) 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 Fe(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-12°. In the third Fe site, Fe(3) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) 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 Cu(1)O6 octahedra. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CuO6 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 Fe(3)O6 octahedra. There are four 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 Cu(1) atom to form OLi2Fe2Cu square pyramids that share corners with five equivalent O(1)Li2Fe2Cu square pyramids and edges with four equivalent O(4)Li2Fe3 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), one Fe(3), and one Cu(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(2), one Fe(1), one Fe(3), and one Cu(1) atom. In the fourth O site, O(4) is bonded to one Li(1), one Li(2), one Fe(1), one Fe(2), and one Fe(3) atom to form OLi2Fe3 square pyramids that share corners with five equivalent O(4)Li2Fe3 square pyramids and edges with four equivalent O(1)Li2Fe2Cu square pyramids.
Li2Fe3CuO8 crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) 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 Fe(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-12°. Both Li(1)-O(1) bond lengths are 2.14 Å. Both Li(1)-O(2) bond lengths are 2.12 Å. Both Li(1)-O(4) bond lengths are 2.28 Å. In the second Li site, Li(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form LiO6 octahedra that share corners with six equivalent Fe(1)O6 octahedra, edges with two equivalent Li(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-11°. Both Li(2)-O(1) bond lengths are 2.29 Å. Both Li(2)-O(3) bond lengths are 2.12 Å. Both Li(2)-O(4) bond lengths are 2.14 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form FeO6 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, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 9-11°. Both Fe(1)-O(1) bond lengths are 2.08 Å. Both Fe(1)-O(3) bond lengths are 2.04 Å. Both Fe(1)-O(4) bond lengths are 2.05 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) 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 Fe(1)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 8-12°. Both Fe(2)-O(1) bond lengths are 2.05 Å. Both Fe(2)-O(2) bond lengths are 2.04 Å. Both Fe(2)-O(4) bond lengths are 2.08 Å. In the third Fe site, Fe(3) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) 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 Cu(1)O6 octahedra. Both Fe(3)-O(2) bond lengths are 2.07 Å. Both Fe(3)-O(3) bond lengths are 1.90 Å. Both Fe(3)-O(4) bond lengths are 1.93 Å. Cu(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CuO6 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 Fe(3)O6 octahedra. Both Cu(1)-O(1) bond lengths are 1.90 Å. Both Cu(1)-O(2) bond lengths are 1.90 Å. Both Cu(1)-O(3) bond lengths are 2.12 Å. There are four 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 Cu(1) atom to form OLi2Fe2Cu square pyramids that share corners with five equivalent O(1)Li2Fe2Cu square pyramids and edges with four equivalent O(4)Li2Fe3 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), one Fe(3), and one Cu(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to one Li(2), one Fe(1), one Fe(3), and one Cu(1) atom. In the fourth O site, O(4) is bonded to one Li(1), one Li(2), one Fe(1), one Fe(2), and one Fe(3) atom to form OLi2Fe3 square pyramids that share corners with five equivalent O(4)Li2Fe3 square pyramids and edges with four equivalent O(1)Li2Fe2Cu square pyramids.