Li3Fe2S4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent S(1) and two equivalent S(2) atoms. In the second Li site, Li(2) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form distorted LiS6 octahedra that share corners with four equivalent Fe(1)S4 tetrahedra, edges with two equivalent Li(2)S6 octahedra, and edges with four equivalent Fe(1)S4 tetrahedra. Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form FeS4 tetrahedra that share corners with two equivalent Li(2)S6 octahedra, corners with two equivalent Fe(1)S4 tetrahedra, edges with two equivalent Li(2)S6 octahedra, and  an edgeedge with one Fe(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-66°. There are two inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Li(1), two equivalent Li(2), and two equivalent Fe(1) atoms to form a mixture of distorted corner and edge-sharing SLi4Fe2 pentagonal pyramids. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Li(2), two equivalent Li(1), and two equivalent Fe(1) atoms.
Li3Fe2S4 crystallizes in the monoclinic C2/c space group. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent S(1) and two equivalent S(2) atoms. There is one shorter (2.50 Å) and one longer (2.71 Å) Li(1)-S(1) bond length. There is one shorter (2.57 Å) and one longer (2.60 Å) Li(1)-S(2) bond length. In the second Li site, Li(2) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form distorted LiS6 octahedra that share corners with four equivalent Fe(1)S4 tetrahedra, edges with two equivalent Li(2)S6 octahedra, and edges with four equivalent Fe(1)S4 tetrahedra. Both Li(2)-S(2) bond lengths are 2.75 Å. There are two shorter (2.58 Å) and two longer (2.76 Å) Li(2)-S(1) bond lengths. Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form FeS4 tetrahedra that share corners with two equivalent Li(2)S6 octahedra, corners with two equivalent Fe(1)S4 tetrahedra, edges with two equivalent Li(2)S6 octahedra, and  an edgeedge with one Fe(1)S4 tetrahedra. The corner-sharing octahedral tilt angles range from 28-66°. Both Fe(1)-S(1) bond lengths are 2.29 Å. Both Fe(1)-S(2) bond lengths are 2.29 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Li(1), two equivalent Li(2), and two equivalent Fe(1) atoms to form a mixture of distorted corner and edge-sharing SLi4Fe2 pentagonal pyramids. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Li(2), two equivalent Li(1), and two equivalent Fe(1) atoms.