Li4Fe7(OF7)2 is beta indium sulfide-derived structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one F(1), one F(2), and one F(7) atom to form LiOF3 tetrahedra that share  a cornercorner with one Fe(5)F6 octahedra,  a cornercorner with one Fe(6)F6 octahedra, corners with two equivalent Fe(1)F6 octahedra, corners with two equivalent Fe(3)O2F4 octahedra, corners with two equivalent Fe(4)O2F4 octahedra, and corners with three equivalent Fe(2)OF5 octahedra. The corner-sharing octahedral tilt angles range from 48-67°. In the second Li site, Li(2) is bonded to one F(3), one F(4), one F(5), and one F(6) atom to form LiF4 tetrahedra that share  a cornercorner with one Fe(1)F6 octahedra,  a cornercorner with one Fe(3)O2F4 octahedra,  a cornercorner with one Fe(4)O2F4 octahedra, corners with two equivalent Fe(5)F6 octahedra, corners with two equivalent Fe(6)F6 octahedra, and corners with three equivalent Fe(2)OF5 octahedra. The corner-sharing octahedral tilt angles range from 50-60°. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form FeF6 octahedra that share corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Li(1)OF3 tetrahedra, edges with two equivalent Fe(3)O2F4 octahedra, edges with two equivalent Fe(4)O2F4 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. In the second Fe site, Fe(2) is bonded to one O(1), one F(1), one F(2), one F(4), one F(5), and one F(6) atom to form FeOF5 octahedra that share corners with three equivalent Li(2)F4 tetrahedra, corners with three equivalent Li(1)OF3 tetrahedra,  an edgeedge with one Fe(1)F6 octahedra,  an edgeedge with one Fe(5)F6 octahedra,  an edgeedge with one Fe(6)F6 octahedra,  an edgeedge with one Fe(3)O2F4 octahedra, and  an edgeedge with one Fe(4)O2F4 octahedra. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent F(2), and two equivalent F(3) atoms to form FeO2F4 octahedra that share corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Li(1)OF3 tetrahedra, edges with two equivalent Fe(1)F6 octahedra, edges with two equivalent Fe(4)O2F4 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. In the fourth Fe site, Fe(4) is bonded to two equivalent O(1), two equivalent F(1), and two equivalent F(3) atoms to form FeO2F4 octahedra that share corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Li(1)OF3 tetrahedra, edges with two equivalent Fe(1)F6 octahedra, edges with two equivalent Fe(3)O2F4 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. In the fifth Fe site, Fe(5) is bonded to two equivalent F(4), two equivalent F(5), and two equivalent F(7) atoms to form FeF6 octahedra that share corners with two equivalent Li(1)OF3 tetrahedra, corners with four equivalent Li(2)F4 tetrahedra, edges with two equivalent Fe(6)F6 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. In the sixth Fe site, Fe(6) is bonded to two equivalent F(5), two equivalent F(6), and two equivalent F(7) atoms to form FeF6 octahedra that share corners with two equivalent Li(1)OF3 tetrahedra, corners with four equivalent Li(2)F4 tetrahedra, edges with two equivalent Fe(5)F6 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. O(1) is bonded to one Li(1), one Fe(2), one Fe(3), and one Fe(4) atom to form corner-sharing OLiFe3 tetrahedra. There are seven inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Li(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the second F site, F(2) is bonded in a rectangular see-saw-like geometry to one Li(1), one Fe(1), one Fe(2), and one Fe(3) atom. In the third F site, F(3) is bonded in a rectangular see-saw-like geometry to one Li(2), one Fe(1), one Fe(3), and one Fe(4) atom. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(2), and one Fe(5) atom. In the fifth F site, F(5) is bonded in a rectangular see-saw-like geometry to one Li(2), one Fe(2), one Fe(5), and one Fe(6) atom. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(2), and one Fe(6) atom. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(5), and one Fe(6) atom.
Li4Fe7(OF7)2 is beta indium sulfide-derived structured and crystallizes in the triclinic P-1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one O(1), one F(1), one F(2), and one F(7) atom to form LiOF3 tetrahedra that share  a cornercorner with one Fe(5)F6 octahedra,  a cornercorner with one Fe(6)F6 octahedra, corners with two equivalent Fe(1)F6 octahedra, corners with two equivalent Fe(3)O2F4 octahedra, corners with two equivalent Fe(4)O2F4 octahedra, and corners with three equivalent Fe(2)OF5 octahedra. The corner-sharing octahedral tilt angles range from 48-67°. The Li(1)-O(1) bond length is 2.05 Å. The Li(1)-F(1) bond length is 2.00 Å. The Li(1)-F(2) bond length is 2.03 Å. The Li(1)-F(7) bond length is 2.00 Å. In the second Li site, Li(2) is bonded to one F(3), one F(4), one F(5), and one F(6) atom to form LiF4 tetrahedra that share  a cornercorner with one Fe(1)F6 octahedra,  a cornercorner with one Fe(3)O2F4 octahedra,  a cornercorner with one Fe(4)O2F4 octahedra, corners with two equivalent Fe(5)F6 octahedra, corners with two equivalent Fe(6)F6 octahedra, and corners with three equivalent Fe(2)OF5 octahedra. The corner-sharing octahedral tilt angles range from 50-60°. The Li(2)-F(3) bond length is 1.98 Å. The Li(2)-F(4) bond length is 1.95 Å. The Li(2)-F(5) bond length is 1.97 Å. The Li(2)-F(6) bond length is 1.96 Å. There are six inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent F(1), two equivalent F(2), and two equivalent F(3) atoms to form FeF6 octahedra that share corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Li(1)OF3 tetrahedra, edges with two equivalent Fe(3)O2F4 octahedra, edges with two equivalent Fe(4)O2F4 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. Both Fe(1)-F(1) bond lengths are 2.14 Å. Both Fe(1)-F(2) bond lengths are 2.09 Å. Both Fe(1)-F(3) bond lengths are 2.13 Å. In the second Fe site, Fe(2) is bonded to one O(1), one F(1), one F(2), one F(4), one F(5), and one F(6) atom to form FeOF5 octahedra that share corners with three equivalent Li(2)F4 tetrahedra, corners with three equivalent Li(1)OF3 tetrahedra,  an edgeedge with one Fe(1)F6 octahedra,  an edgeedge with one Fe(5)F6 octahedra,  an edgeedge with one Fe(6)F6 octahedra,  an edgeedge with one Fe(3)O2F4 octahedra, and  an edgeedge with one Fe(4)O2F4 octahedra. The Fe(2)-O(1) bond length is 2.00 Å. The Fe(2)-F(1) bond length is 2.22 Å. The Fe(2)-F(2) bond length is 2.29 Å. The Fe(2)-F(4) bond length is 2.13 Å. The Fe(2)-F(5) bond length is 2.26 Å. The Fe(2)-F(6) bond length is 2.03 Å. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent F(2), and two equivalent F(3) atoms to form FeO2F4 octahedra that share corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Li(1)OF3 tetrahedra, edges with two equivalent Fe(1)F6 octahedra, edges with two equivalent Fe(4)O2F4 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. Both Fe(3)-O(1) bond lengths are 2.00 Å. Both Fe(3)-F(2) bond lengths are 2.27 Å. Both Fe(3)-F(3) bond lengths are 2.26 Å. In the fourth Fe site, Fe(4) is bonded to two equivalent O(1), two equivalent F(1), and two equivalent F(3) atoms to form FeO2F4 octahedra that share corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Li(1)OF3 tetrahedra, edges with two equivalent Fe(1)F6 octahedra, edges with two equivalent Fe(3)O2F4 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. Both Fe(4)-O(1) bond lengths are 2.00 Å. Both Fe(4)-F(1) bond lengths are 2.30 Å. Both Fe(4)-F(3) bond lengths are 2.25 Å. In the fifth Fe site, Fe(5) is bonded to two equivalent F(4), two equivalent F(5), and two equivalent F(7) atoms to form FeF6 octahedra that share corners with two equivalent Li(1)OF3 tetrahedra, corners with four equivalent Li(2)F4 tetrahedra, edges with two equivalent Fe(6)F6 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. Both Fe(5)-F(4) bond lengths are 2.05 Å. Both Fe(5)-F(5) bond lengths are 2.17 Å. Both Fe(5)-F(7) bond lengths are 2.13 Å. In the sixth Fe site, Fe(6) is bonded to two equivalent F(5), two equivalent F(6), and two equivalent F(7) atoms to form FeF6 octahedra that share corners with two equivalent Li(1)OF3 tetrahedra, corners with four equivalent Li(2)F4 tetrahedra, edges with two equivalent Fe(5)F6 octahedra, and edges with two equivalent Fe(2)OF5 octahedra. Both Fe(6)-F(5) bond lengths are 2.18 Å. Both Fe(6)-F(6) bond lengths are 2.13 Å. Both Fe(6)-F(7) bond lengths are 2.06 Å. O(1) is bonded to one Li(1), one Fe(2), one Fe(3), and one Fe(4) atom to form corner-sharing OLiFe3 tetrahedra. There are seven inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Li(1), one Fe(1), one Fe(2), and one Fe(4) atom. In the second F site, F(2) is bonded in a rectangular see-saw-like geometry to one Li(1), one Fe(1), one Fe(2), and one Fe(3) atom. In the third F site, F(3) is bonded in a rectangular see-saw-like geometry to one Li(2), one Fe(1), one Fe(3), and one Fe(4) atom. In the fourth F site, F(4) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(2), and one Fe(5) atom. In the fifth F site, F(5) is bonded in a rectangular see-saw-like geometry to one Li(2), one Fe(2), one Fe(5), and one Fe(6) atom. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(2), and one Fe(6) atom. In the seventh F site, F(7) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(5), and one Fe(6) atom.