Materials Data on Li4SnSe4 by Materials Project

Abstract

Li4SnSe4 is Aluminum carbonitride-like structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are three inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six Se2- atoms to form LiSe6 octahedra that share corners with two equivalent SnSe4 tetrahedra, corners with eight LiSe4 tetrahedra, edges with two equivalent LiSe6 octahedra, edges with two equivalent LiSe4 tetrahedra, edges with two equivalent SnSe4 tetrahedra, and faces with two equivalent LiSe4 tetrahedra. There are a spread of Li–Se bond distances ranging from 2.78–3.01 Å. In the second Li1+ site, Li1+ is bonded to four Se2- atoms to form LiSe4 tetrahedra that share corners with three equivalent LiSe6 octahedra, corners with four equivalent SnSe4 tetrahedra, corners with eight LiSe4 tetrahedra, and a faceface with one LiSe6 octahedra. The corner-sharing octahedra tilt angles range from 14–49°. There are a spread of Li–Se bond distances ranging from 2.56–2.71 Å. In the third Li1+ site, Li1+ is bonded to four Se2- atoms to form LiSe4 tetrahedra that share corners with two equivalent LiSe6 octahedra, corners with two equivalent SnSe4 tetrahedra, corners with eight equivalent LiSe4 tetrahedra, edges with two equivalent LiSe6 octahedra, and an edgeedge with one SnSe4 tetrahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Li–Se bond distances ranging from 2.60–2.70 Å. Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share corners with two equivalent LiSe6 octahedra, corners with ten LiSe4 tetrahedra, edges with two equivalent LiSe6 octahedra, and an edgeedge with one LiSe4 tetrahedra. The corner-sharing octahedral tilt angles are 52°. There are three shorter (2.55 Å) and one longer (2.59 Å) Sn–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to five Li1+ and one Sn4+ atom. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to five Li1+ and one Sn4+ atom. In the third Se2- site, Se2- is bonded to four Li1+ and one Sn4+ atom to form distorted corner-sharing SeLi4Sn trigonal bipyramids.