Li(FeO2)2 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1) and three equivalent O(2) atoms to form LiO4 tetrahedra that share corners with three equivalent Li(2)O6 octahedra and corners with nine equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-60°. In the second Li site, Li(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form LiO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, and edges with six equivalent Fe(1)O6 octahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, edges with two equivalent Li(2)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(4) and three equivalent O(3) atoms to form FeO4 tetrahedra that share corners with three equivalent Li(2)O6 octahedra and corners with nine equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-59°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Li(1) and three equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded to one Li(2), one Fe(2), and two equivalent Fe(1) atoms to form a mixture of distorted corner and edge-sharing OLiFe3 trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Fe(2) and three equivalent Fe(1) atoms.
Li(FeO2)2 is Spinel-like structured and crystallizes in the trigonal R3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1) and three equivalent O(2) atoms to form LiO4 tetrahedra that share corners with three equivalent Li(2)O6 octahedra and corners with nine equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-60°. The Li(1)-O(1) bond length is 1.96 Å. All Li(1)-O(2) bond lengths are 1.98 Å. In the second Li site, Li(2) is bonded to three equivalent O(2) and three equivalent O(3) atoms to form LiO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, and edges with six equivalent Fe(1)O6 octahedra. All Li(2)-O(2) bond lengths are 2.08 Å. All Li(2)-O(3) bond lengths are 2.11 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form FeO6 octahedra that share corners with three equivalent Li(1)O4 tetrahedra, corners with three equivalent Fe(2)O4 tetrahedra, edges with two equivalent Li(2)O6 octahedra, and edges with four equivalent Fe(1)O6 octahedra. The Fe(1)-O(1) bond length is 2.03 Å. The Fe(1)-O(4) bond length is 2.12 Å. Both Fe(1)-O(2) bond lengths are 1.92 Å. Both Fe(1)-O(3) bond lengths are 2.03 Å. In the second Fe site, Fe(2) is bonded to one O(4) and three equivalent O(3) atoms to form FeO4 tetrahedra that share corners with three equivalent Li(2)O6 octahedra and corners with nine equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 57-59°. The Fe(2)-O(4) bond length is 1.96 Å. All Fe(2)-O(3) bond lengths are 1.92 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Li(1) and three equivalent Fe(1) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Li(1), one Li(2), and two equivalent Fe(1) atoms. In the third O site, O(3) is bonded to one Li(2), one Fe(2), and two equivalent Fe(1) atoms to form a mixture of distorted corner and edge-sharing OLiFe3 trigonal pyramids. In the fourth O site, O(4) is bonded in a distorted rectangular see-saw-like geometry to one Fe(2) and three equivalent Fe(1) atoms.