Li5CuF8 is Spinel-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one F(2) and three equivalent F(1) atoms to form LiF4 tetrahedra that share corners with three equivalent Cu(1)F6 octahedra and corners with nine equivalent Li(2)F6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. In the second Li site, Li(2) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form LiF6 octahedra that share corners with six equivalent Li(1)F4 tetrahedra, edges with two equivalent Cu(1)F6 octahedra, and edges with four equivalent Li(2)F6 octahedra. Cu(1) is bonded to six equivalent F(1) atoms to form CuF6 octahedra that share corners with six equivalent Li(1)F4 tetrahedra and edges with six equivalent Li(2)F6 octahedra. There are two inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Li(1), two equivalent Li(2), and one Cu(1) atom. In the second F site, F(2) is bonded to one Li(1) and three equivalent Li(2) atoms to form distorted corner-sharing FLi4 trigonal pyramids.
Li5CuF8 is Spinel-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one F(2) and three equivalent F(1) atoms to form LiF4 tetrahedra that share corners with three equivalent Cu(1)F6 octahedra and corners with nine equivalent Li(2)F6 octahedra. The corner-sharing octahedral tilt angles range from 56-59°. The Li(1)-F(2) bond length is 1.80 Å. All Li(1)-F(1) bond lengths are 1.91 Å. In the second Li site, Li(2) is bonded to two equivalent F(2) and four equivalent F(1) atoms to form LiF6 octahedra that share corners with six equivalent Li(1)F4 tetrahedra, edges with two equivalent Cu(1)F6 octahedra, and edges with four equivalent Li(2)F6 octahedra. Both Li(2)-F(2) bond lengths are 1.91 Å. All Li(2)-F(1) bond lengths are 2.04 Å. Cu(1) is bonded to six equivalent F(1) atoms to form CuF6 octahedra that share corners with six equivalent Li(1)F4 tetrahedra and edges with six equivalent Li(2)F6 octahedra. All Cu(1)-F(1) bond lengths are 1.89 Å. There are two inequivalent F sites. In the first F site, F(1) is bonded in a rectangular see-saw-like geometry to one Li(1), two equivalent Li(2), and one Cu(1) atom. In the second F site, F(2) is bonded to one Li(1) and three equivalent Li(2) atoms to form distorted corner-sharing FLi4 trigonal pyramids.