LiFeF4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one F(3), one F(4), one F(7), and two equivalent F(5) atoms. In the second Li site, Li(2) is bonded to one F(1), one F(5), one F(6), and two equivalent F(7) atoms to form distorted LiF5 square pyramids that share corners with two equivalent Li(2)F5 square pyramids,  an edgeedge with one Fe(2)F6 octahedra, and edges with two equivalent Fe(1)F6 octahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one F(2), one F(3), one F(7), one F(9), and two equivalent F(1) atoms to form FeF6 octahedra that share  a cornercorner with one Fe(2)F6 octahedra, corners with three equivalent Fe(1)F6 octahedra, and edges with two equivalent Li(2)F5 square pyramids. The corner-sharing octahedral tilt angles range from 0-18°. In the second Fe site, Fe(2) is bonded to one F(2), one F(5), one F(6), one F(8), and two equivalent F(4) atoms to form FeF6 octahedra that share  a cornercorner with one Fe(1)F6 octahedra, corners with three equivalent Fe(2)F6 octahedra, and  an edgeedge with one Li(2)F5 square pyramid. The corner-sharing octahedral tilt angles range from 0-11°. There are nine inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Li(2) and two equivalent Fe(1) atoms. In the second F site, F(2) is bonded in a linear geometry to one Fe(1) and one Fe(2) atom. In the third F site, F(3) is bonded in a bent 120 degrees geometry to one Li(1) and one Fe(1) atom. In the fourth F site, F(4) is bonded in a T-shaped geometry to one Li(1) and two equivalent Fe(2) atoms. In the fifth F site, F(5) is bonded to one Li(2), two equivalent Li(1), and one Fe(2) atom to form a mixture of corner and edge-sharing FLi3Fe trigonal pyramids. In the sixth F site, F(6) is bonded in a water-like geometry to one Li(2) and one Fe(2) atom. In the seventh F site, F(7) is bonded to one Li(1), two equivalent Li(2), and one Fe(1) atom to form a mixture of corner and edge-sharing FLi3Fe tetrahedra. In the eighth F site, F(8) is bonded in a linear geometry to two equivalent Fe(2) atoms. In the ninth F site, F(9) is bonded in a linear geometry to two equivalent Fe(1) atoms.
LiFeF4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 5-coordinate geometry to one F(3), one F(4), one F(7), and two equivalent F(5) atoms. The Li(1)-F(3) bond length is 1.88 Å. The Li(1)-F(4) bond length is 2.35 Å. The Li(1)-F(7) bond length is 2.08 Å. Both Li(1)-F(5) bond lengths are 2.05 Å. In the second Li site, Li(2) is bonded to one F(1), one F(5), one F(6), and two equivalent F(7) atoms to form distorted LiF5 square pyramids that share corners with two equivalent Li(2)F5 square pyramids,  an edgeedge with one Fe(2)F6 octahedra, and edges with two equivalent Fe(1)F6 octahedra. The Li(2)-F(1) bond length is 2.36 Å. The Li(2)-F(5) bond length is 2.11 Å. The Li(2)-F(6) bond length is 1.97 Å. Both Li(2)-F(7) bond lengths are 2.10 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one F(2), one F(3), one F(7), one F(9), and two equivalent F(1) atoms to form FeF6 octahedra that share  a cornercorner with one Fe(2)F6 octahedra, corners with three equivalent Fe(1)F6 octahedra, and edges with two equivalent Li(2)F5 square pyramids. The corner-sharing octahedral tilt angles range from 0-18°. The Fe(1)-F(2) bond length is 1.94 Å. The Fe(1)-F(3) bond length is 1.86 Å. The Fe(1)-F(7) bond length is 2.01 Å. The Fe(1)-F(9) bond length is 2.01 Å. Both Fe(1)-F(1) bond lengths are 1.99 Å. In the second Fe site, Fe(2) is bonded to one F(2), one F(5), one F(6), one F(8), and two equivalent F(4) atoms to form FeF6 octahedra that share  a cornercorner with one Fe(1)F6 octahedra, corners with three equivalent Fe(2)F6 octahedra, and  an edgeedge with one Li(2)F5 square pyramid. The corner-sharing octahedral tilt angles range from 0-11°. The Fe(2)-F(2) bond length is 1.99 Å. The Fe(2)-F(5) bond length is 1.96 Å. The Fe(2)-F(6) bond length is 1.89 Å. The Fe(2)-F(8) bond length is 1.94 Å. Both Fe(2)-F(4) bond lengths are 1.97 Å. There are nine inequivalent F sites. In the first F site, F(1) is bonded in a distorted T-shaped geometry to one Li(2) and two equivalent Fe(1) atoms. In the second F site, F(2) is bonded in a linear geometry to one Fe(1) and one Fe(2) atom. In the third F site, F(3) is bonded in a bent 120 degrees geometry to one Li(1) and one Fe(1) atom. In the fourth F site, F(4) is bonded in a T-shaped geometry to one Li(1) and two equivalent Fe(2) atoms. In the fifth F site, F(5) is bonded to one Li(2), two equivalent Li(1), and one Fe(2) atom to form a mixture of corner and edge-sharing FLi3Fe trigonal pyramids. In the sixth F site, F(6) is bonded in a water-like geometry to one Li(2) and one Fe(2) atom. In the seventh F site, F(7) is bonded to one Li(1), two equivalent Li(2), and one Fe(1) atom to form a mixture of corner and edge-sharing FLi3Fe tetrahedra. In the eighth F site, F(8) is bonded in a linear geometry to two equivalent Fe(2) atoms. In the ninth F site, F(9) is bonded in a linear geometry to two equivalent Fe(1) atoms.