Materials Data on Ba7Sn3Se13 by Materials Project
Ba7Sn3Se13 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to six Se2- atoms to form distorted BaSe6 pentagonal pyramids that share a cornercorner with one SnSe4 tetrahedra, edges with two SnSe4 tetrahedra, and a faceface with one BaSe6 pentagonal pyramid. There are a spread of Ba–Se bond distances ranging from 3.23–3.60 Å. In the second Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.36–3.89 Å. In the third Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.39–3.67 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.28–3.89 Å. There are two inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share a cornercorner with one BaSe6 pentagonal pyramid and an edgeedge with one BaSe6 pentagonal pyramid. There are two shorter (2.56 Å) and two longer (2.57 Å) Sn–Se bond lengths. In the second Sn4+ site, Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share edges with two equivalent BaSe6 pentagonal pyramids. There are a spread of Sn–Se bond distances ranging from 2.52–2.58 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to four Ba2+ and one Sn4+ atom. In the second Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ba2+ and one Sn4+ atom. In the third Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ba2+ and one Sn4+ atom. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ba2+ and one Sn4+ atom. In the fifth Se2- site, Se2- is bonded in a 6-coordinate geometry to five Ba2+ and one Sn4+ atom. In the sixth Se2- site, Se2- is bonded in a 6-coordinate geometry to five Ba2+ and one Sn4+ atom. In the seventh Se2- site, Se2- is bonded in a 5-coordinate geometry to six Ba2+ atoms. In the eighth Se2- site, Se2- is bonded in a 4-coordinate geometry to three Ba2+ and one Sn4+ atom.