Materials Data on Li8CaSn7 by Materials Project

Abstract

Li8CaSn7 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are five inequivalent Li sites. In the first Li site, Li is bonded in a 8-coordinate geometry to two equivalent Li, one Ca, and five Sn atoms. Both Li–Li bond lengths are 2.96 Å. The Li–Ca bond length is 3.16 Å. There are one shorter (2.77 Å) and four longer (2.96 Å) Li–Sn bond lengths. In the second Li site, Li is bonded in a 9-coordinate geometry to one Ca and six Sn atoms. The Li–Ca bond length is 3.22 Å. There are a spread of Li–Sn bond distances ranging from 2.88–3.32 Å. In the third Li site, Li is bonded in a 4-coordinate geometry to two equivalent Li and five Sn atoms. Both Li–Li bond lengths are 2.98 Å. There are a spread of Li–Sn bond distances ranging from 2.87–3.28 Å. In the fourth Li site, Li is bonded in a 3-coordinate geometry to one Li, one Ca, and five Sn atoms. The Li–Li bond length is 3.01 Å. The Li–Ca bond length is 3.21 Å. There are a spread of Li–Sn bond distances ranging from 2.81–3.08 Å. In the fifth Li site, Li is bonded to eight Li and four equivalent Sn atoms to form a mixture of corner and face-sharing LiLi8Sn4 cuboctahedra. All Li–Sn bond lengths are 3.23 Å. Ca is bonded in a 10-coordinate geometry to five Li and ten Sn atoms. There are a spread of Ca–Sn bond distances ranging from 3.38–3.46 Å. There are five inequivalent Sn sites. In the first Sn site, Sn is bonded in a 6-coordinate geometry to four Li and two equivalent Sn atoms. Both Sn–Sn bond lengths are 3.08 Å. In the second Sn site, Sn is bonded in a 7-coordinate geometry to seven Li and two equivalent Sn atoms. In the third Sn site, Sn is bonded in a 9-coordinate geometry to five Li, two equivalent Ca, and one Sn atom. The Sn–Sn bond length is 2.95 Å. In the fourth Sn site, Sn is bonded in a 4-coordinate geometry to four equivalent Li and two equivalent Ca atoms. In the fifth Sn site, Sn is bonded in a 12-coordinate geometry to eight Li, two equivalent Ca, and two Sn atoms. The Sn–Sn bond length is 2.96 Å.