Li3Fe2F7 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one F(1), one F(2), one F(3), and one F(7) atom to form LiF4 tetrahedra that share corners with three equivalent Fe(2)F6 octahedra, corners with two equivalent Li(2)F4 tetrahedra, corners with three equivalent Fe(1)F5 trigonal bipyramids, and  an edgeedge with one Li(3)F5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 25-60°. In the second Li site, Li(2) is bonded to one F(2), one F(3), one F(4), and one F(6) atom to form LiF4 tetrahedra that share  a cornercorner with one Fe(2)F6 octahedra, corners with two equivalent Li(1)F4 tetrahedra, corners with two equivalent Fe(1)F5 trigonal bipyramids, corners with three equivalent Li(3)F5 trigonal bipyramids, and  an edgeedge with one Fe(2)F6 octahedra. The corner-sharing octahedral tilt angles are 64°. In the third Li site, Li(3) is bonded to one F(2), one F(4), one F(5), one F(6), and one F(7) atom to form distorted LiF5 trigonal bipyramids that share corners with three equivalent Li(2)F4 tetrahedra,  a cornercorner with one Fe(1)F5 trigonal bipyramid, edges with two equivalent Fe(2)F6 octahedra,  an edgeedge with one Li(1)F4 tetrahedra, and  an edgeedge with one Fe(1)F5 trigonal bipyramid. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one F(1), one F(3), one F(4), one F(5), and one F(7) atom to form FeF5 trigonal bipyramids that share corners with two equivalent Fe(2)F6 octahedra, corners with two equivalent Li(2)F4 tetrahedra, corners with three equivalent Li(1)F4 tetrahedra,  a cornercorner with one Li(3)F5 trigonal bipyramid,  an edgeedge with one Fe(2)F6 octahedra, and  an edgeedge with one Li(3)F5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 51-55°. In the second Fe site, Fe(2) is bonded to one F(1), one F(2), one F(3), one F(6), and two equivalent F(5) atoms to form distorted FeF6 octahedra that share  a cornercorner with one Li(2)F4 tetrahedra, corners with three equivalent Li(1)F4 tetrahedra, corners with two equivalent Fe(1)F5 trigonal bipyramids,  an edgeedge with one Fe(2)F6 octahedra,  an edgeedge with one Li(2)F4 tetrahedra,  an edgeedge with one Fe(1)F5 trigonal bipyramid, and edges with two equivalent Li(3)F5 trigonal bipyramids. There are seven inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Fe(2) atom. In the second F site, F(2) is bonded in a distorted see-saw-like geometry to one Li(1), one Li(2), one Li(3), and one Fe(2) atom. In the third F site, F(3) is bonded to one Li(1), one Li(2), one Fe(1), and one Fe(2) atom to form distorted corner-sharing FLi2Fe2 tetrahedra. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Li(2), one Li(3), and one Fe(1) atom. In the fifth F site, F(5) is bonded to one Li(3), one Fe(1), and two equivalent Fe(2) atoms to form FLiFe3 trigonal pyramids that share corners with three equivalent F(3)Li2Fe2 tetrahedra and  an edgeedge with one F(5)LiFe3 trigonal pyramid. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Li(3), and one Fe(2) atom. In the seventh F site, F(7) is bonded in a T-shaped geometry to one Li(1), one Li(3), and one Fe(1) atom.
Li3Fe2F7 crystallizes in the monoclinic P2_1/c space group. There are three inequivalent Li sites. In the first Li site, Li(1) is bonded to one F(1), one F(2), one F(3), and one F(7) atom to form LiF4 tetrahedra that share corners with three equivalent Fe(2)F6 octahedra, corners with two equivalent Li(2)F4 tetrahedra, corners with three equivalent Fe(1)F5 trigonal bipyramids, and  an edgeedge with one Li(3)F5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 25-60°. The Li(1)-F(1) bond length is 1.86 Å. The Li(1)-F(2) bond length is 1.93 Å. The Li(1)-F(3) bond length is 1.89 Å. The Li(1)-F(7) bond length is 1.84 Å. In the second Li site, Li(2) is bonded to one F(2), one F(3), one F(4), and one F(6) atom to form LiF4 tetrahedra that share  a cornercorner with one Fe(2)F6 octahedra, corners with two equivalent Li(1)F4 tetrahedra, corners with two equivalent Fe(1)F5 trigonal bipyramids, corners with three equivalent Li(3)F5 trigonal bipyramids, and  an edgeedge with one Fe(2)F6 octahedra. The corner-sharing octahedral tilt angles are 64°. The Li(2)-F(2) bond length is 2.00 Å. The Li(2)-F(3) bond length is 1.95 Å. The Li(2)-F(4) bond length is 1.88 Å. The Li(2)-F(6) bond length is 1.87 Å. In the third Li site, Li(3) is bonded to one F(2), one F(4), one F(5), one F(6), and one F(7) atom to form distorted LiF5 trigonal bipyramids that share corners with three equivalent Li(2)F4 tetrahedra,  a cornercorner with one Fe(1)F5 trigonal bipyramid, edges with two equivalent Fe(2)F6 octahedra,  an edgeedge with one Li(1)F4 tetrahedra, and  an edgeedge with one Fe(1)F5 trigonal bipyramid. The Li(3)-F(2) bond length is 2.16 Å. The Li(3)-F(4) bond length is 1.94 Å. The Li(3)-F(5) bond length is 2.15 Å. The Li(3)-F(6) bond length is 1.94 Å. The Li(3)-F(7) bond length is 1.94 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one F(1), one F(3), one F(4), one F(5), and one F(7) atom to form FeF5 trigonal bipyramids that share corners with two equivalent Fe(2)F6 octahedra, corners with two equivalent Li(2)F4 tetrahedra, corners with three equivalent Li(1)F4 tetrahedra,  a cornercorner with one Li(3)F5 trigonal bipyramid,  an edgeedge with one Fe(2)F6 octahedra, and  an edgeedge with one Li(3)F5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 51-55°. The Fe(1)-F(1) bond length is 2.07 Å. The Fe(1)-F(3) bond length is 2.11 Å. The Fe(1)-F(4) bond length is 2.10 Å. The Fe(1)-F(5) bond length is 2.07 Å. The Fe(1)-F(7) bond length is 2.01 Å. In the second Fe site, Fe(2) is bonded to one F(1), one F(2), one F(3), one F(6), and two equivalent F(5) atoms to form distorted FeF6 octahedra that share  a cornercorner with one Li(2)F4 tetrahedra, corners with three equivalent Li(1)F4 tetrahedra, corners with two equivalent Fe(1)F5 trigonal bipyramids,  an edgeedge with one Fe(2)F6 octahedra,  an edgeedge with one Li(2)F4 tetrahedra,  an edgeedge with one Fe(1)F5 trigonal bipyramid, and edges with two equivalent Li(3)F5 trigonal bipyramids. The Fe(2)-F(1) bond length is 2.10 Å. The Fe(2)-F(2) bond length is 2.01 Å. The Fe(2)-F(3) bond length is 2.23 Å. The Fe(2)-F(6) bond length is 1.99 Å. There is one shorter (2.20 Å) and one longer (2.30 Å) Fe(2)-F(5) bond length. There are seven inequivalent F sites. In the first F site, F(1) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Fe(2) atom. In the second F site, F(2) is bonded in a distorted see-saw-like geometry to one Li(1), one Li(2), one Li(3), and one Fe(2) atom. In the third F site, F(3) is bonded to one Li(1), one Li(2), one Fe(1), and one Fe(2) atom to form distorted corner-sharing FLi2Fe2 tetrahedra. In the fourth F site, F(4) is bonded in a distorted T-shaped geometry to one Li(2), one Li(3), and one Fe(1) atom. In the fifth F site, F(5) is bonded to one Li(3), one Fe(1), and two equivalent Fe(2) atoms to form FLiFe3 trigonal pyramids that share corners with three equivalent F(3)Li2Fe2 tetrahedra and  an edgeedge with one F(5)LiFe3 trigonal pyramid. In the sixth F site, F(6) is bonded in a distorted trigonal planar geometry to one Li(2), one Li(3), and one Fe(2) atom. In the seventh F site, F(7) is bonded in a T-shaped geometry to one Li(1), one Li(3), and one Fe(1) atom.