Li3(FeO2)4 crystallizes in the triclinic P1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form LiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. In the second Li site, Li(2) is bonded to one O(3), one O(4), one O(6), and one O(8) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. In the third Li site, Li(3) is bonded to one O(1), one O(2), one O(5), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(7), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. In the third Fe site, Fe(3) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(2), one O(6), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(3), one Fe(1), and one Fe(4) atom to form corner-sharing OLi2Fe2 tetrahedra. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(3), one Fe(2), and one Fe(4) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Fe(1), and one Fe(3) atom to form corner-sharing OLi2Fe2 tetrahedra. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(2), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(3), one Fe(2), and one Fe(3) atom to form corner-sharing OLi2Fe2 tetrahedra. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Fe(2), and one Fe(4) atom to form corner-sharing OLi2Fe2 tetrahedra. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to one Li(3), one Fe(1), and one Fe(3) atom. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Li(2), one Fe(1), and one Fe(4) atom.
Li3(FeO2)4 crystallizes in the triclinic P1 space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(3), one O(5), and one O(6) atom to form LiO4 tetrahedra that share corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. The Li(1)-O(1) bond length is 2.06 Å. The Li(1)-O(3) bond length is 2.06 Å. The Li(1)-O(5) bond length is 2.03 Å. The Li(1)-O(6) bond length is 2.04 Å. In the second Li site, Li(2) is bonded to one O(3), one O(4), one O(6), and one O(8) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. The Li(2)-O(3) bond length is 2.08 Å. The Li(2)-O(4) bond length is 1.97 Å. The Li(2)-O(6) bond length is 2.02 Å. The Li(2)-O(8) bond length is 1.99 Å. In the third Li site, Li(3) is bonded to one O(1), one O(2), one O(5), and one O(7) atom to form LiO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, corners with two equivalent Fe(2)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. The Li(3)-O(1) bond length is 2.08 Å. The Li(3)-O(2) bond length is 1.99 Å. The Li(3)-O(5) bond length is 2.07 Å. The Li(3)-O(7) bond length is 2.01 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(3), one O(7), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.91 Å. The Fe(1)-O(3) bond length is 1.90 Å. The Fe(1)-O(7) bond length is 1.85 Å. The Fe(1)-O(8) bond length is 1.85 Å. In the second Fe site, Fe(2) is bonded to one O(2), one O(4), one O(5), and one O(6) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(3)O4 tetrahedra, and corners with two equivalent Fe(4)O4 tetrahedra. The Fe(2)-O(2) bond length is 1.88 Å. The Fe(2)-O(4) bond length is 1.90 Å. The Fe(2)-O(5) bond length is 1.92 Å. The Fe(2)-O(6) bond length is 1.93 Å. In the third Fe site, Fe(3) is bonded to one O(3), one O(4), one O(5), and one O(7) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. The Fe(3)-O(3) bond length is 1.92 Å. The Fe(3)-O(4) bond length is 1.86 Å. The Fe(3)-O(5) bond length is 1.91 Å. The Fe(3)-O(7) bond length is 1.89 Å. In the fourth Fe site, Fe(4) is bonded to one O(1), one O(2), one O(6), and one O(8) atom to form FeO4 tetrahedra that share corners with two equivalent Li(1)O4 tetrahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with two equivalent Li(3)O4 tetrahedra, corners with two equivalent Fe(1)O4 tetrahedra, and corners with two equivalent Fe(2)O4 tetrahedra. The Fe(4)-O(1) bond length is 1.92 Å. The Fe(4)-O(2) bond length is 1.88 Å. The Fe(4)-O(6) bond length is 1.92 Å. The Fe(4)-O(8) bond length is 1.91 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Li(1), one Li(3), one Fe(1), and one Fe(4) atom to form corner-sharing OLi2Fe2 tetrahedra. In the second O site, O(2) is bonded in a trigonal planar geometry to one Li(3), one Fe(2), and one Fe(4) atom. In the third O site, O(3) is bonded to one Li(1), one Li(2), one Fe(1), and one Fe(3) atom to form corner-sharing OLi2Fe2 tetrahedra. In the fourth O site, O(4) is bonded in a trigonal planar geometry to one Li(2), one Fe(2), and one Fe(3) atom. In the fifth O site, O(5) is bonded to one Li(1), one Li(3), one Fe(2), and one Fe(3) atom to form corner-sharing OLi2Fe2 tetrahedra. In the sixth O site, O(6) is bonded to one Li(1), one Li(2), one Fe(2), and one Fe(4) atom to form corner-sharing OLi2Fe2 tetrahedra. In the seventh O site, O(7) is bonded in a trigonal non-coplanar geometry to one Li(3), one Fe(1), and one Fe(3) atom. In the eighth O site, O(8) is bonded in a trigonal non-coplanar geometry to one Li(2), one Fe(1), and one Fe(4) atom.