Li2FeS2 crystallizes in the trigonal P3m1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one S(1) and three equivalent S(2) atoms to form distorted LiS4 tetrahedra that share corners with six equivalent Li(2)S6 octahedra, corners with six equivalent Li(1)S4 tetrahedra, edges with three equivalent Li(2)S6 octahedra, and edges with three equivalent Fe(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-52°. In the second Li site, Li(2) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form LiS6 octahedra that share corners with six equivalent Li(1)S4 tetrahedra, corners with six equivalent Fe(1)S4 tetrahedra, edges with six equivalent Li(2)S6 octahedra, edges with three equivalent Li(1)S4 tetrahedra, and edges with three equivalent Fe(1)S4 tetrahedra. Fe(1) is bonded to one S(2) and three equivalent S(1) atoms to form distorted FeS4 tetrahedra that share corners with six equivalent Li(2)S6 octahedra, corners with six equivalent Fe(1)S4 tetrahedra, edges with three equivalent Li(2)S6 octahedra, and edges with three equivalent Li(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-59°. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Li(1), three equivalent Li(2), and three equivalent Fe(1) atoms to form distorted edge-sharing SLi4Fe3 pentagonal bipyramids. In the second S site, S(2) is bonded in a 7-coordinate geometry to three equivalent Li(1), three equivalent Li(2), and one Fe(1) atom.
Li2FeS2 crystallizes in the trigonal P3m1 space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded to one S(1) and three equivalent S(2) atoms to form distorted LiS4 tetrahedra that share corners with six equivalent Li(2)S6 octahedra, corners with six equivalent Li(1)S4 tetrahedra, edges with three equivalent Li(2)S6 octahedra, and edges with three equivalent Fe(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-52°. The Li(1)-S(1) bond length is 2.49 Å. All Li(1)-S(2) bond lengths are 2.32 Å. In the second Li site, Li(2) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form LiS6 octahedra that share corners with six equivalent Li(1)S4 tetrahedra, corners with six equivalent Fe(1)S4 tetrahedra, edges with six equivalent Li(2)S6 octahedra, edges with three equivalent Li(1)S4 tetrahedra, and edges with three equivalent Fe(1)S4 tetrahedra. All Li(2)-S(1) bond lengths are 2.85 Å. All Li(2)-S(2) bond lengths are 2.62 Å. Fe(1) is bonded to one S(2) and three equivalent S(1) atoms to form distorted FeS4 tetrahedra that share corners with six equivalent Li(2)S6 octahedra, corners with six equivalent Fe(1)S4 tetrahedra, edges with three equivalent Li(2)S6 octahedra, and edges with three equivalent Li(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 19-59°. The Fe(1)-S(2) bond length is 2.34 Å. All Fe(1)-S(1) bond lengths are 2.37 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to one Li(1), three equivalent Li(2), and three equivalent Fe(1) atoms to form distorted edge-sharing SLi4Fe3 pentagonal bipyramids. In the second S site, S(2) is bonded in a 7-coordinate geometry to three equivalent Li(1), three equivalent Li(2), and one Fe(1) atom.