Materials Data on Li2Fe3S4 by Materials Project
Li2Fe3S4 is Spinel-like structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Li1+ is bonded to four S2- atoms to form LiS4 trigonal pyramids that share corners with six equivalent FeS4 tetrahedra, corners with two equivalent LiS4 trigonal pyramids, corners with four equivalent FeS4 trigonal pyramids, an edgeedge with one FeS4 trigonal pyramid, and edges with two equivalent LiS4 trigonal pyramids. There are a spread of Li–S bond distances ranging from 2.41–2.55 Å. There are two inequivalent Fe2+ sites. In the first Fe2+ site, Fe2+ is bonded to four S2- atoms to form FeS4 tetrahedra that share corners with four equivalent FeS4 tetrahedra, corners with two equivalent FeS4 trigonal pyramids, corners with six equivalent LiS4 trigonal pyramids, and an edgeedge with one FeS4 tetrahedra. There are a spread of Fe–S bond distances ranging from 2.30–2.33 Å. In the second Fe2+ site, Fe2+ is bonded to four equivalent S2- atoms to form distorted FeS4 trigonal pyramids that share corners with four equivalent FeS4 tetrahedra, corners with eight equivalent LiS4 trigonal pyramids, edges with two equivalent LiS4 trigonal pyramids, and edges with two equivalent FeS4 trigonal pyramids. There are two shorter (2.38 Å) and two longer (2.42 Å) Fe–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to three equivalent Li1+ and three Fe2+ atoms to form distorted SLi3Fe3 octahedra that share corners with five equivalent SLi3Fe3 octahedra, corners with six equivalent SLiFe3 tetrahedra, edges with two equivalent SLi3Fe3 octahedra, and a faceface with one SLi3Fe3 octahedra. The corner-sharing octahedra tilt angles range from 42–80°. In the second S2- site, S2- is bonded to one Li1+ and three equivalent Fe2+ atoms to form distorted SLiFe3 tetrahedra that share corners with six equivalent SLi3Fe3 octahedra, corners with four equivalent SLiFe3 tetrahedra, and an edgeedge with one SLiFe3 tetrahedra. The corner-sharing octahedra tilt angles range from 60–74°.