Materials Data on Ba6Sn7S20 by Materials Project

Abstract

Ba6Sn7S20 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.13–3.45 Å. In the second Ba2+ site, Ba2+ is bonded in a 9-coordinate geometry to nine S2- atoms. There are a spread of Ba–S bond distances ranging from 3.25–3.73 Å. In the third Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.18–3.63 Å. There are four inequivalent Sn4+ sites. In the first Sn4+ site, Sn4+ is bonded to five S2- atoms to form distorted SnS5 trigonal bipyramids that share a cornercorner with one SnS4 tetrahedra and an edgeedge with one SnS5 trigonal bipyramid. There are a spread of Sn–S bond distances ranging from 2.37–2.85 Å. In the second Sn4+ site, Sn4+ is bonded to five S2- atoms to form SnS5 trigonal bipyramids that share a cornercorner with one SnS4 tetrahedra and edges with two SnS5 trigonal bipyramids. There are a spread of Sn–S bond distances ranging from 2.42–2.71 Å. In the third Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share corners with two equivalent SnS4 tetrahedra and corners with two equivalent SnS5 trigonal bipyramids. There are two shorter (2.41 Å) and two longer (2.47 Å) Sn–S bond lengths. In the fourth Sn4+ site, Sn4+ is bonded to four S2- atoms to form SnS4 tetrahedra that share a cornercorner with one SnS4 tetrahedra and a cornercorner with one SnS5 trigonal bipyramid. There are a spread of Sn–S bond distances ranging from 2.36–2.52 Å. There are ten inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to three equivalent Ba2+ and one Sn4+ atom. In the second S2- site, S2- is bonded to two Ba2+ and two Sn4+ atoms to form distorted SBa2Sn2 trigonal pyramids that share corners with two equivalent SBa3Sn tetrahedra and corners with four SBa2Sn2 trigonal pyramids. In the third S2- site, S2- is bonded to three Ba2+ and one Sn4+ atom to form a mixture of distorted edge and corner-sharing SBa3Sn tetrahedra. In the fourth S2- site, S2- is bonded in a 4-coordinate geometry to three Ba2+ and one Sn4+ atom. In the fifth S2- site, S2- is bonded to three Ba2+ and one Sn4+ atom to form distorted SBa3Sn trigonal pyramids that share corners with two equivalent SBa3Sn tetrahedra, corners with four SBa2Sn2 trigonal pyramids, an edgeedge with one SBa3Sn tetrahedra, and an edgeedge with one SBa2Sn2 trigonal pyramid. In the sixth S2- site, S2- is bonded to two Ba2+ and two Sn4+ atoms to form distorted SBa2Sn2 trigonal pyramids that share a cornercorner with one SBa3Sn tetrahedra, corners with two equivalent SBa2Sn2 trigonal pyramids, an edgeedge with one SBa3Sn tetrahedra, and an edgeedge with one SBa3Sn trigonal pyramid. In the seventh S2- site, S2- is bonded in a 5-coordinate geometry to three Ba2+ and two equivalent Sn4+ atoms. In the eighth S2- site, S2- is bonded in a 2-coordinate geometry to one Ba2+ and two Sn4+ atoms. In the ninth S2- site, S2- is bonded in a 5-coordinate geometry to three Ba2+ and two Sn4+ atoms. In the tenth S2- site, S2- is bonded in a 4-coordinate geometry to two Ba2+ and two Sn4+ atoms.