Li2Fe2S3 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a distorted see-saw-like geometry to one S(1) and three equivalent S(2) atoms. Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form a mixture of distorted corner and edge-sharing FeS4 tetrahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Li(1) and four equivalent Fe(1) atoms to form SLi2Fe4 octahedra that share corners with four equivalent S(1)Li2Fe4 octahedra, corners with six equivalent S(2)Li3Fe2 square pyramids, and edges with four equivalent S(2)Li3Fe2 square pyramids. The corner-sharing octahedral tilt angles are 49°. In the second S site, S(2) is bonded to three equivalent Li(1) and two equivalent Fe(1) atoms to form distorted SLi3Fe2 square pyramids that share corners with three equivalent S(1)Li2Fe4 octahedra, corners with four equivalent S(2)Li3Fe2 square pyramids, edges with two equivalent S(1)Li2Fe4 octahedra, and edges with two equivalent S(2)Li3Fe2 square pyramids. The corner-sharing octahedral tilt angles range from 44-75°.
Li2Fe2S3 crystallizes in the monoclinic P2_1/c space group. Li(1) is bonded in a distorted see-saw-like geometry to one S(1) and three equivalent S(2) atoms. The Li(1)-S(1) bond length is 2.59 Å. There are a spread of Li(1)-S(2) bond distances ranging from 2.42-2.49 Å. Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form a mixture of distorted corner and edge-sharing FeS4 tetrahedra. There is one shorter (2.40 Å) and one longer (2.42 Å) Fe(1)-S(1) bond length. There is one shorter (2.30 Å) and one longer (2.40 Å) Fe(1)-S(2) bond length. There are two inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Li(1) and four equivalent Fe(1) atoms to form SLi2Fe4 octahedra that share corners with four equivalent S(1)Li2Fe4 octahedra, corners with six equivalent S(2)Li3Fe2 square pyramids, and edges with four equivalent S(2)Li3Fe2 square pyramids. The corner-sharing octahedral tilt angles are 49°. In the second S site, S(2) is bonded to three equivalent Li(1) and two equivalent Fe(1) atoms to form distorted SLi3Fe2 square pyramids that share corners with three equivalent S(1)Li2Fe4 octahedra, corners with four equivalent S(2)Li3Fe2 square pyramids, edges with two equivalent S(1)Li2Fe4 octahedra, and edges with two equivalent S(2)Li3Fe2 square pyramids. The corner-sharing octahedral tilt angles range from 44-75°.