Materials Data on Li7Sn3 by Materials Project

Abstract

Li7Sn3 crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of one Li7Sn3 sheet oriented in the (1, 0, 0) direction. there are seven inequivalent Li sites. In the first Li site, Li is bonded to two equivalent Li and four Sn atoms to form distorted LiLi2Sn4 tetrahedra that share corners with four LiLiSn4 tetrahedra, edges with six LiLi2Sn4 tetrahedra, and a faceface with one LiLi3Sn4 tetrahedra. Both Li–Li bond lengths are 2.87 Å. There are a spread of Li–Sn bond distances ranging from 2.81–2.88 Å. In the second Li site, Li is bonded to one Li and four Sn atoms to form distorted LiLiSn4 tetrahedra that share corners with five LiLi2Sn4 tetrahedra, edges with five LiLi2Sn4 tetrahedra, and faces with two equivalent LiLi3Sn4 tetrahedra. The Li–Li bond length is 2.85 Å. There are three shorter (2.89 Å) and one longer (2.90 Å) Li–Sn bond lengths. In the third Li site, Li is bonded to three equivalent Li and four Sn atoms to form a mixture of distorted corner, edge, and face-sharing LiLi3Sn4 tetrahedra. There are one shorter (2.88 Å) and two longer (2.91 Å) Li–Li bond lengths. There are a spread of Li–Sn bond distances ranging from 2.81–2.84 Å. In the fourth Li site, Li is bonded in a 12-coordinate geometry to eight Li and six Sn atoms. There are one shorter (2.90 Å) and one longer (3.00 Å) Li–Li bond lengths. There are a spread of Li–Sn bond distances ranging from 3.25–3.34 Å. In the fifth Li site, Li is bonded in a 2-coordinate geometry to two equivalent Sn atoms. Both Li–Sn bond lengths are 2.96 Å. In the sixth Li site, Li is bonded in a distorted trigonal non-coplanar geometry to one Li and three Sn atoms. There are two shorter (2.90 Å) and one longer (2.94 Å) Li–Sn bond lengths. In the seventh Li site, Li is bonded in a distorted trigonal non-coplanar geometry to one Li and three Sn atoms. There are two shorter (2.91 Å) and one longer (2.94 Å) Li–Sn bond lengths. There are three inequivalent Sn sites. In the first Sn site, Sn is bonded in a 6-coordinate geometry to seven Li atoms. In the second Sn site, Sn is bonded in a 7-coordinate geometry to nine Li atoms. In the third Sn site, Sn is bonded in a 7-coordinate geometry to ten Li atoms.