Li2Fe3F8 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one F(1), one F(2), one F(4), and two equivalent F(3) atoms to form distorted LiF5 trigonal bipyramids that share corners with three equivalent Fe(1)F6 octahedra,  a cornercorner with one Fe(2)F5 trigonal bipyramid,  an edgeedge with one Fe(1)F6 octahedra,  an edgeedge with one Li(1)F5 trigonal bipyramid, and  an edgeedge with one Fe(2)F5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 54-67°. In the second Li site, Li(2) is bonded to one F(5), one F(6), one F(7), and one F(8) atom to form LiF4 tetrahedra that share corners with three equivalent Fe(2)F5 trigonal bipyramids and  an edgeedge with one Fe(1)F6 octahedra. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one F(2), one F(3), one F(5), one F(6), and two equivalent F(1) atoms to form distorted FeF6 octahedra that share corners with three equivalent Li(1)F5 trigonal bipyramids, corners with four equivalent Fe(2)F5 trigonal bipyramids,  an edgeedge with one Fe(1)F6 octahedra,  an edgeedge with one Li(2)F4 tetrahedra, and  an edgeedge with one Li(1)F5 trigonal bipyramid. In the second Fe site, Fe(2) is bonded to one F(2), one F(3), one F(5), one F(6), and one F(8) atom to form FeF5 trigonal bipyramids that share corners with four equivalent Fe(1)F6 octahedra, corners with three equivalent Li(2)F4 tetrahedra,  a cornercorner with one Li(1)F5 trigonal bipyramid, and  an edgeedge with one Li(1)F5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 41-53°. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one F(8), two equivalent F(4), and two equivalent F(7) atoms. There are eight inequivalent F sites. In the first F site, F(7) is bonded in a distorted trigonal planar geometry to one Li(2) and two equivalent Fe(3) atoms. In the second F site, F(8) is bonded in a trigonal planar geometry to one Li(2), one Fe(2), and one Fe(3) atom. In the third F site, F(1) is bonded in a distorted T-shaped geometry to one Li(1) and two equivalent Fe(1) atoms. In the fourth F site, F(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Fe(2) atom. In the fifth F site, F(3) is bonded to two equivalent Li(1), one Fe(1), and one Fe(2) atom to form distorted edge-sharing FLi2Fe2 trigonal pyramids. In the sixth F site, F(4) is bonded in a distorted trigonal planar geometry to one Li(1) and two equivalent Fe(3) atoms. In the seventh F site, F(5) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Fe(2) atom. In the eighth F site, F(6) is bonded in a 3-coordinate geometry to one Li(2), one Fe(1), and one Fe(2) atom.
Li2Fe3F8 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one F(1), one F(2), one F(4), and two equivalent F(3) atoms to form distorted LiF5 trigonal bipyramids that share corners with three equivalent Fe(1)F6 octahedra,  a cornercorner with one Fe(2)F5 trigonal bipyramid,  an edgeedge with one Fe(1)F6 octahedra,  an edgeedge with one Li(1)F5 trigonal bipyramid, and  an edgeedge with one Fe(2)F5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 54-67°. The Li(1)-F(1) bond length is 1.95 Å. The Li(1)-F(2) bond length is 1.89 Å. The Li(1)-F(4) bond length is 1.85 Å. There is one shorter (1.94 Å) and one longer (2.35 Å) Li(1)-F(3) bond length. In the second Li site, Li(2) is bonded to one F(5), one F(6), one F(7), and one F(8) atom to form LiF4 tetrahedra that share corners with three equivalent Fe(2)F5 trigonal bipyramids and  an edgeedge with one Fe(1)F6 octahedra. The Li(2)-F(5) bond length is 1.88 Å. The Li(2)-F(6) bond length is 1.87 Å. The Li(2)-F(7) bond length is 1.83 Å. The Li(2)-F(8) bond length is 1.91 Å. There are three inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one F(2), one F(3), one F(5), one F(6), and two equivalent F(1) atoms to form distorted FeF6 octahedra that share corners with three equivalent Li(1)F5 trigonal bipyramids, corners with four equivalent Fe(2)F5 trigonal bipyramids,  an edgeedge with one Fe(1)F6 octahedra,  an edgeedge with one Li(2)F4 tetrahedra, and  an edgeedge with one Li(1)F5 trigonal bipyramid. The Fe(1)-F(2) bond length is 2.03 Å. The Fe(1)-F(3) bond length is 2.12 Å. The Fe(1)-F(5) bond length is 2.12 Å. The Fe(1)-F(6) bond length is 2.24 Å. There is one shorter (2.12 Å) and one longer (2.14 Å) Fe(1)-F(1) bond length. In the second Fe site, Fe(2) is bonded to one F(2), one F(3), one F(5), one F(6), and one F(8) atom to form FeF5 trigonal bipyramids that share corners with four equivalent Fe(1)F6 octahedra, corners with three equivalent Li(2)F4 tetrahedra,  a cornercorner with one Li(1)F5 trigonal bipyramid, and  an edgeedge with one Li(1)F5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 41-53°. The Fe(2)-F(2) bond length is 2.12 Å. The Fe(2)-F(3) bond length is 2.20 Å. The Fe(2)-F(5) bond length is 1.95 Å. The Fe(2)-F(6) bond length is 1.96 Å. The Fe(2)-F(8) bond length is 2.18 Å. In the third Fe site, Fe(3) is bonded in a 5-coordinate geometry to one F(8), two equivalent F(4), and two equivalent F(7) atoms. The Fe(3)-F(8) bond length is 2.04 Å. There is one shorter (1.99 Å) and one longer (2.22 Å) Fe(3)-F(4) bond length. There is one shorter (2.05 Å) and one longer (2.23 Å) Fe(3)-F(7) bond length. There are eight inequivalent F sites. In the first F site, F(7) is bonded in a distorted trigonal planar geometry to one Li(2) and two equivalent Fe(3) atoms. In the second F site, F(8) is bonded in a trigonal planar geometry to one Li(2), one Fe(2), and one Fe(3) atom. In the third F site, F(1) is bonded in a distorted T-shaped geometry to one Li(1) and two equivalent Fe(1) atoms. In the fourth F site, F(2) is bonded in a distorted trigonal planar geometry to one Li(1), one Fe(1), and one Fe(2) atom. In the fifth F site, F(3) is bonded to two equivalent Li(1), one Fe(1), and one Fe(2) atom to form distorted edge-sharing FLi2Fe2 trigonal pyramids. In the sixth F site, F(4) is bonded in a distorted trigonal planar geometry to one Li(1) and two equivalent Fe(3) atoms. In the seventh F site, F(5) is bonded in a distorted trigonal planar geometry to one Li(2), one Fe(1), and one Fe(2) atom. In the eighth F site, F(6) is bonded in a 3-coordinate geometry to one Li(2), one Fe(1), and one Fe(2) atom.