Materials Data on Li14Mn2S9 by Materials Project
Li14Mn2S9 crystallizes in the trigonal P-3 space group. The structure is three-dimensional. there are three inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four S2- atoms to form LiS4 tetrahedra that share a cornercorner with one MnS4 tetrahedra, corners with fourteen LiS4 tetrahedra, an edgeedge with one MnS4 tetrahedra, and edges with four LiS4 tetrahedra. There are a spread of Li–S bond distances ranging from 2.45–2.59 Å. In the second Li1+ site, Li1+ is bonded to four equivalent S2- atoms to form LiS4 tetrahedra that share corners with two equivalent MnS4 tetrahedra, corners with twelve LiS4 tetrahedra, an edgeedge with one MnS4 tetrahedra, and edges with four LiS4 tetrahedra. There are a spread of Li–S bond distances ranging from 2.43–2.54 Å. In the third Li1+ site, Li1+ is bonded to four S2- atoms to form LiS4 tetrahedra that share corners with three equivalent MnS4 tetrahedra, corners with ten LiS4 tetrahedra, and edges with six LiS4 tetrahedra. There are three shorter (2.46 Å) and one longer (2.50 Å) Li–S bond lengths. Mn2+ is bonded to four S2- atoms to form MnS4 tetrahedra that share corners with twelve LiS4 tetrahedra and edges with six LiS4 tetrahedra. There are one shorter (2.38 Å) and three longer (2.39 Å) Mn–S bond lengths. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded to six Li1+ and one Mn2+ atom to form a mixture of distorted edge and corner-sharing SLi6Mn hexagonal pyramids. In the second S2- site, S2- is bonded in a 7-coordinate geometry to six equivalent Li1+ and one Mn2+ atom. In the third S2- site, S2- is bonded in a body-centered cubic geometry to eight Li1+ atoms.