Li4FeO3F is Aluminum carbonitride-derived structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(3), and one F(1) atom to form LiO3F tetrahedra that share corners with three equivalent Li(3)O5 square pyramids, corners with four equivalent Fe(1)O3F tetrahedra, and  an edgeedge with one Li(3)O5 square pyramid. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. In the third Li site, Li(3) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted LiO5 square pyramids that share  a cornercorner with one Fe(1)O3F tetrahedra, corners with three equivalent Li(1)O3F tetrahedra, edges with two equivalent Li(3)O5 square pyramids,  an edgeedge with one Li(1)O3F tetrahedra, and edges with two equivalent Fe(1)O3F tetrahedra. In the fourth Li site, Li(4) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent F(1) atoms. Fe(1) is bonded to one O(1), one O(2), one O(3), and one F(1) atom to form FeO3F tetrahedra that share  a cornercorner with one Li(3)O5 square pyramid, corners with four equivalent Li(1)O3F tetrahedra, and edges with two equivalent Li(3)O5 square pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Li(1), one Li(2), one Li(3), two equivalent Li(4), and one Fe(1) atom. In the second O site, O(2) is bonded to one Li(1), two equivalent Li(2), two equivalent Li(3), and one Fe(1) atom to form distorted OLi5Fe octahedra that share corners with two equivalent O(3)Li5Fe octahedra, corners with two equivalent F(1)Li3Fe tetrahedra, edges with two equivalent O(2)Li5Fe octahedra, and edges with four equivalent O(3)Li5Fe octahedra. The corner-sharing octahedral tilt angles range from 17-27°. In the third O site, O(3) is bonded to one Li(1), two equivalent Li(2), two equivalent Li(3), and one Fe(1) atom to form distorted OLi5Fe octahedra that share corners with two equivalent O(2)Li5Fe octahedra, corners with two equivalent F(1)Li3Fe tetrahedra, edges with two equivalent O(3)Li5Fe octahedra, and edges with four equivalent O(2)Li5Fe octahedra. The corner-sharing octahedral tilt angles range from 17-27°. F(1) is bonded to one Li(1), two equivalent Li(4), and one Fe(1) atom to form FLi3Fe tetrahedra that share corners with two equivalent O(2)Li5Fe octahedra, corners with two equivalent O(3)Li5Fe octahedra, and  an edgeedge with one F(1)Li3Fe tetrahedra. The corner-sharing octahedral tilt angles range from 62-67°.
Li4FeO3F is Aluminum carbonitride-derived structured and crystallizes in the triclinic P-1 space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one O(2), one O(3), and one F(1) atom to form LiO3F tetrahedra that share corners with three equivalent Li(3)O5 square pyramids, corners with four equivalent Fe(1)O3F tetrahedra, and  an edgeedge with one Li(3)O5 square pyramid. The Li(1)-O(1) bond length is 1.92 Å. The Li(1)-O(2) bond length is 1.94 Å. The Li(1)-O(3) bond length is 1.92 Å. The Li(1)-F(1) bond length is 2.12 Å. In the second Li site, Li(2) is bonded in a 5-coordinate geometry to one O(1), two equivalent O(2), and two equivalent O(3) atoms. The Li(2)-O(1) bond length is 2.54 Å. There is one shorter (2.04 Å) and one longer (2.12 Å) Li(2)-O(2) bond length. There is one shorter (1.97 Å) and one longer (2.12 Å) Li(2)-O(3) bond length. In the third Li site, Li(3) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form distorted LiO5 square pyramids that share  a cornercorner with one Fe(1)O3F tetrahedra, corners with three equivalent Li(1)O3F tetrahedra, edges with two equivalent Li(3)O5 square pyramids,  an edgeedge with one Li(1)O3F tetrahedra, and edges with two equivalent Fe(1)O3F tetrahedra. The Li(3)-O(1) bond length is 2.21 Å. There is one shorter (2.04 Å) and one longer (2.16 Å) Li(3)-O(2) bond length. There is one shorter (2.04 Å) and one longer (2.40 Å) Li(3)-O(3) bond length. In the fourth Li site, Li(4) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent F(1) atoms. There is one shorter (1.95 Å) and one longer (2.00 Å) Li(4)-O(1) bond length. There is one shorter (2.08 Å) and one longer (2.11 Å) Li(4)-F(1) bond length. Fe(1) is bonded to one O(1), one O(2), one O(3), and one F(1) atom to form FeO3F tetrahedra that share  a cornercorner with one Li(3)O5 square pyramid, corners with four equivalent Li(1)O3F tetrahedra, and edges with two equivalent Li(3)O5 square pyramids. The Fe(1)-O(1) bond length is 1.85 Å. The Fe(1)-O(2) bond length is 1.86 Å. The Fe(1)-O(3) bond length is 1.85 Å. The Fe(1)-F(1) bond length is 2.04 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Li(1), one Li(2), one Li(3), two equivalent Li(4), and one Fe(1) atom. In the second O site, O(2) is bonded to one Li(1), two equivalent Li(2), two equivalent Li(3), and one Fe(1) atom to form distorted OLi5Fe octahedra that share corners with two equivalent O(3)Li5Fe octahedra, corners with two equivalent F(1)Li3Fe tetrahedra, edges with two equivalent O(2)Li5Fe octahedra, and edges with four equivalent O(3)Li5Fe octahedra. The corner-sharing octahedral tilt angles range from 17-27°. In the third O site, O(3) is bonded to one Li(1), two equivalent Li(2), two equivalent Li(3), and one Fe(1) atom to form distorted OLi5Fe octahedra that share corners with two equivalent O(2)Li5Fe octahedra, corners with two equivalent F(1)Li3Fe tetrahedra, edges with two equivalent O(3)Li5Fe octahedra, and edges with four equivalent O(2)Li5Fe octahedra. The corner-sharing octahedral tilt angles range from 17-27°. F(1) is bonded to one Li(1), two equivalent Li(4), and one Fe(1) atom to form FLi3Fe tetrahedra that share corners with two equivalent O(2)Li5Fe octahedra, corners with two equivalent O(3)Li5Fe octahedra, and  an edgeedge with one F(1)Li3Fe tetrahedra. The corner-sharing octahedral tilt angles range from 62-67°.