Li2FeF4 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(2), one F(3), and two equivalent F(1) atoms to form LiF4 tetrahedra that share corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Fe(1)F4 tetrahedra, and  an edgeedge with one Li(1)F4 tetrahedra. In the second Li site, Li(2) is bonded to one F(2), one F(3), and two equivalent F(4) atoms to form LiF4 tetrahedra that share corners with two equivalent Li(1)F4 tetrahedra, corners with two equivalent Li(2)F4 tetrahedra, and corners with four equivalent Fe(1)F4 tetrahedra. Fe(1) is bonded to one F(1), one F(2), one F(3), and one F(4) atom to form FeF4 tetrahedra that share corners with four equivalent Li(1)F4 tetrahedra and corners with four equivalent Li(2)F4 tetrahedra. There are four inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to two equivalent Li(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Fe(1) atom. In the third F site, F(3) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Fe(1) atom. In the fourth F site, F(4) is bonded in a trigonal planar geometry to two equivalent Li(2) and one Fe(1) atom.
Li2FeF4 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(2), one F(3), and two equivalent F(1) atoms to form LiF4 tetrahedra that share corners with two equivalent Li(2)F4 tetrahedra, corners with four equivalent Fe(1)F4 tetrahedra, and  an edgeedge with one Li(1)F4 tetrahedra. The Li(1)-F(2) bond length is 1.91 Å. The Li(1)-F(3) bond length is 1.91 Å. There is one shorter (1.90 Å) and one longer (1.91 Å) Li(1)-F(1) bond length. In the second Li site, Li(2) is bonded to one F(2), one F(3), and two equivalent F(4) atoms to form LiF4 tetrahedra that share corners with two equivalent Li(1)F4 tetrahedra, corners with two equivalent Li(2)F4 tetrahedra, and corners with four equivalent Fe(1)F4 tetrahedra. The Li(2)-F(2) bond length is 1.91 Å. The Li(2)-F(3) bond length is 1.92 Å. There is one shorter (1.90 Å) and one longer (1.91 Å) Li(2)-F(4) bond length. Fe(1) is bonded to one F(1), one F(2), one F(3), and one F(4) atom to form FeF4 tetrahedra that share corners with four equivalent Li(1)F4 tetrahedra and corners with four equivalent Li(2)F4 tetrahedra. The Fe(1)-F(1) bond length is 1.99 Å. The Fe(1)-F(2) bond length is 1.97 Å. The Fe(1)-F(3) bond length is 1.96 Å. The Fe(1)-F(4) bond length is 2.02 Å. There are four inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to two equivalent Li(1) and one Fe(1) atom. In the second F site, F(2) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Fe(1) atom. In the third F site, F(3) is bonded in a trigonal planar geometry to one Li(1), one Li(2), and one Fe(1) atom. In the fourth F site, F(4) is bonded in a trigonal planar geometry to two equivalent Li(2) and one Fe(1) atom.