Li4FeO3F is Aluminum carbonitride-derived structured and crystallizes in the monoclinic Cc space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. In the second Li site, Li(2) is bonded to one O(1), one O(2), and two equivalent F(1) atoms to form LiO2F2 tetrahedra that share corners with two equivalent Li(2)O2F2 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with four equivalent Li(3)O3F tetrahedra, and corners with four equivalent Fe(1)O3F tetrahedra. In the third Li site, Li(3) 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 two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O3F tetrahedra, corners with four equivalent Li(2)O2F2 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra, and  an edgeedge with one Fe(1)O3F tetrahedra. In the fourth Li site, Li(4) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(2)O2F2 tetrahedra, corners with two equivalent Li(3)O3F tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O3F tetrahedra,  an edgeedge with one Li(3)O3F tetrahedra, and  an edgeedge with one Fe(1)O3F tetrahedra. 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 corners with two equivalent Li(3)O3F tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with four equivalent Li(2)O2F2 tetrahedra,  an edgeedge with one Li(3)O3F tetrahedra, and  an edgeedge with one Li(4)O4 tetrahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Li(2), one Li(3), one Li(4), two equivalent Li(1), and one Fe(1) atom. In the second O site, O(2) is bonded in a distorted pentagonal planar geometry to one Li(1), one Li(2), one Li(3), one Li(4), and one Fe(1) atom. In the third O site, O(3) is bonded in a distorted pentagonal planar geometry to one Li(1), one Li(3), two equivalent Li(4), and one Fe(1) atom. F(1) is bonded to one Li(3), two equivalent Li(2), and one Fe(1) atom to form corner-sharing FLi3Fe tetrahedra.
Li4FeO3F is Aluminum carbonitride-derived structured and crystallizes in the monoclinic Cc space group. There are four inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(1) atoms. The Li(1)-O(2) bond length is 1.95 Å. The Li(1)-O(3) bond length is 1.92 Å. There is one shorter (2.13 Å) and one longer (2.24 Å) Li(1)-O(1) bond length. In the second Li site, Li(2) is bonded to one O(1), one O(2), and two equivalent F(1) atoms to form LiO2F2 tetrahedra that share corners with two equivalent Li(2)O2F2 tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with four equivalent Li(3)O3F tetrahedra, and corners with four equivalent Fe(1)O3F tetrahedra. The Li(2)-O(1) bond length is 2.05 Å. The Li(2)-O(2) bond length is 1.97 Å. There is one shorter (1.93 Å) and one longer (2.01 Å) Li(2)-F(1) bond length. In the third Li site, Li(3) 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 two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O3F tetrahedra, corners with four equivalent Li(2)O2F2 tetrahedra,  an edgeedge with one Li(4)O4 tetrahedra, and  an edgeedge with one Fe(1)O3F tetrahedra. The Li(3)-O(1) bond length is 2.02 Å. The Li(3)-O(2) bond length is 1.98 Å. The Li(3)-O(3) bond length is 2.01 Å. The Li(3)-F(1) bond length is 2.10 Å. In the fourth Li site, Li(4) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form LiO4 tetrahedra that share corners with two equivalent Li(2)O2F2 tetrahedra, corners with two equivalent Li(3)O3F tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with two equivalent Fe(1)O3F tetrahedra,  an edgeedge with one Li(3)O3F tetrahedra, and  an edgeedge with one Fe(1)O3F tetrahedra. The Li(4)-O(1) bond length is 1.99 Å. The Li(4)-O(2) bond length is 2.01 Å. There is one shorter (1.91 Å) and one longer (1.93 Å) Li(4)-O(3) 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 corners with two equivalent Li(3)O3F tetrahedra, corners with two equivalent Li(4)O4 tetrahedra, corners with four equivalent Li(2)O2F2 tetrahedra,  an edgeedge with one Li(3)O3F tetrahedra, and  an edgeedge with one Li(4)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.88 Å. The Fe(1)-O(2) bond length is 1.86 Å. The Fe(1)-O(3) bond length is 1.86 Å. The Fe(1)-F(1) bond length is 2.06 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Li(2), one Li(3), one Li(4), two equivalent Li(1), and one Fe(1) atom. In the second O site, O(2) is bonded in a distorted pentagonal planar geometry to one Li(1), one Li(2), one Li(3), one Li(4), and one Fe(1) atom. In the third O site, O(3) is bonded in a distorted pentagonal planar geometry to one Li(1), one Li(3), two equivalent Li(4), and one Fe(1) atom. F(1) is bonded to one Li(3), two equivalent Li(2), and one Fe(1) atom to form corner-sharing FLi3Fe tetrahedra.