Li5(FeO2)4 crystallizes in the monoclinic Cc space group. There are five inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. In the third Li site, Li(3) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form LiO6 octahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Li(5)O4 tetrahedra, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and  a faceface with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-10°. In the fourth Li site, Li(4) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom. In the fifth Li site, Li(5) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form LiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, corners with three equivalent Li(3)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-63°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra, corners with three equivalent Li(3)O6 octahedra, corners with three equivalent Li(5)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra,  an edgeedge with one Fe(4)O6 octahedra, and  a faceface with one Li(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-52°. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(5)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and  an edgeedge with one Li(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-48°. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(5)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and  an edgeedge with one Li(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-52°. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(5)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and  an edgeedge with one Li(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-50°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to one Li(2), one Li(3), one Li(4), one Li(5), one Fe(1), one Fe(3), and one Fe(4) atom. In the second O site, O(2) is bonded to one Li(1), one Li(3), one Li(4), one Fe(1), one Fe(2), and one Fe(3) atom to form edge-sharing OLi3Fe3 octahedra. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(4), one Fe(2), one Fe(3), and one Fe(4) atom to form distorted edge-sharing OLi3Fe3 pentagonal pyramids. In the fourth O site, O(4) is bonded in a 7-coordinate geometry to one Li(1), one Li(2), one Li(3), one Li(5), one Fe(1), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(2), one Li(3), one Fe(1), one Fe(2), and one Fe(4) atom to form edge-sharing OLi3Fe3 octahedra. In the sixth O site, O(6) is bonded to one Li(2), one Li(3), one Li(4), one Fe(1), one Fe(3), and one Fe(4) atom to form edge-sharing OLi3Fe3 octahedra. In the seventh O site, O(7) is bonded in a 7-coordinate geometry to one Li(1), one Li(3), one Li(4), one Li(5), one Fe(1), one Fe(2), and one Fe(4) atom. In the eighth O site, O(8) is bonded in a 7-coordinate geometry to one Li(1), one Li(2), one Li(4), one Li(5), one Fe(2), one Fe(3), and one Fe(4) atom.
Li5(FeO2)4 crystallizes in the monoclinic Cc space group. There are five inequivalent Li sites. In the first Li site, Li(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom. The Li(1)-O(2) bond length is 1.97 Å. The Li(1)-O(3) bond length is 2.02 Å. The Li(1)-O(4) bond length is 2.29 Å. The Li(1)-O(5) bond length is 2.03 Å. The Li(1)-O(7) bond length is 2.44 Å. The Li(1)-O(8) bond length is 2.41 Å. In the second Li site, Li(2) is bonded in a 3-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), and one O(8) atom. The Li(2)-O(1) bond length is 2.41 Å. The Li(2)-O(3) bond length is 2.09 Å. The Li(2)-O(4) bond length is 2.41 Å. The Li(2)-O(5) bond length is 1.96 Å. The Li(2)-O(6) bond length is 2.00 Å. The Li(2)-O(8) bond length is 2.46 Å. In the third Li site, Li(3) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form LiO6 octahedra that share corners with three equivalent Fe(1)O6 octahedra, corners with three equivalent Li(5)O4 tetrahedra, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and  a faceface with one Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-10°. The Li(3)-O(1) bond length is 2.23 Å. The Li(3)-O(2) bond length is 2.15 Å. The Li(3)-O(4) bond length is 2.23 Å. The Li(3)-O(5) bond length is 2.11 Å. The Li(3)-O(6) bond length is 2.18 Å. The Li(3)-O(7) bond length is 2.18 Å. In the fourth Li site, Li(4) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(6), one O(7), and one O(8) atom. The Li(4)-O(1) bond length is 2.35 Å. The Li(4)-O(2) bond length is 1.94 Å. The Li(4)-O(3) bond length is 2.05 Å. The Li(4)-O(6) bond length is 1.93 Å. The Li(4)-O(7) bond length is 2.42 Å. The Li(4)-O(8) bond length is 2.25 Å. In the fifth Li site, Li(5) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form LiO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(3)O6 octahedra,  a cornercorner with one Fe(4)O6 octahedra, corners with three equivalent Li(3)O6 octahedra, corners with three equivalent Fe(1)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 12-63°. The Li(5)-O(1) bond length is 1.88 Å. The Li(5)-O(4) bond length is 1.88 Å. The Li(5)-O(7) bond length is 1.91 Å. The Li(5)-O(8) bond length is 1.88 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with two equivalent Fe(2)O6 octahedra, corners with two equivalent Fe(3)O6 octahedra, corners with two equivalent Fe(4)O6 octahedra, corners with three equivalent Li(3)O6 octahedra, corners with three equivalent Li(5)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra,  an edgeedge with one Fe(4)O6 octahedra, and  a faceface with one Li(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 7-52°. The Fe(1)-O(1) bond length is 2.09 Å. The Fe(1)-O(2) bond length is 2.10 Å. The Fe(1)-O(4) bond length is 2.06 Å. The Fe(1)-O(5) bond length is 2.13 Å. The Fe(1)-O(6) bond length is 2.08 Å. The Fe(1)-O(7) bond length is 2.15 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(5)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and  an edgeedge with one Li(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-48°. The Fe(2)-O(2) bond length is 2.04 Å. The Fe(2)-O(3) bond length is 2.05 Å. The Fe(2)-O(4) bond length is 2.10 Å. The Fe(2)-O(5) bond length is 2.08 Å. The Fe(2)-O(7) bond length is 2.10 Å. The Fe(2)-O(8) bond length is 2.01 Å. In the third Fe site, Fe(3) is bonded to one O(1), one O(2), one O(3), one O(4), one O(6), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(5)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(4)O6 octahedra, and  an edgeedge with one Li(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-52°. The Fe(3)-O(1) bond length is 2.16 Å. The Fe(3)-O(2) bond length is 2.11 Å. The Fe(3)-O(3) bond length is 2.15 Å. The Fe(3)-O(4) bond length is 2.21 Å. The Fe(3)-O(6) bond length is 2.17 Å. The Fe(3)-O(8) bond length is 2.16 Å. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(3), one O(5), one O(6), one O(7), and one O(8) atom to form FeO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra,  a cornercorner with one Li(5)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, edges with two equivalent Li(3)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(3)O6 octahedra, and  an edgeedge with one Li(5)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-50°. The Fe(4)-O(1) bond length is 2.11 Å. The Fe(4)-O(3) bond length is 2.05 Å. The Fe(4)-O(5) bond length is 2.08 Å. The Fe(4)-O(6) bond length is 2.04 Å. The Fe(4)-O(7) bond length is 2.15 Å. The Fe(4)-O(8) bond length is 2.05 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 7-coordinate geometry to one Li(2), one Li(3), one Li(4), one Li(5), one Fe(1), one Fe(3), and one Fe(4) atom. In the second O site, O(2) is bonded to one Li(1), one Li(3), one Li(4), one Fe(1), one Fe(2), and one Fe(3) atom to form edge-sharing OLi3Fe3 octahedra. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Li(4), one Fe(2), one Fe(3), and one Fe(4) atom to form distorted edge-sharing OLi3Fe3 pentagonal pyramids. In the fourth O site, O(4) is bonded in a 7-coordinate geometry to one Li(1), one Li(2), one Li(3), one Li(5), one Fe(1), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(2), one Li(3), one Fe(1), one Fe(2), and one Fe(4) atom to form edge-sharing OLi3Fe3 octahedra. In the sixth O site, O(6) is bonded to one Li(2), one Li(3), one Li(4), one Fe(1), one Fe(3), and one Fe(4) atom to form edge-sharing OLi3Fe3 octahedra. In the seventh O site, O(7) is bonded in a 7-coordinate geometry to one Li(1), one Li(3), one Li(4), one Li(5), one Fe(1), one Fe(2), and one Fe(4) atom. In the eighth O site, O(8) is bonded in a 7-coordinate geometry to one Li(1), one Li(2), one Li(4), one Li(5), one Fe(2), one Fe(3), and one Fe(4) atom.