Materials Data on Ba2SnSe4 by Materials Project
Ba2SnSe4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first 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 3.29–3.86 Å. In the second Ba2+ site, Ba2+ is bonded to seven Se2- atoms to form distorted BaSe7 pentagonal bipyramids that share corners with four equivalent BaSe7 pentagonal bipyramids, a cornercorner with one SnSe4 tetrahedra, an edgeedge with one BaSe7 pentagonal bipyramid, and edges with three equivalent SnSe4 tetrahedra. There are a spread of Ba–Se bond distances ranging from 3.24–3.70 Å. Sn4+ is bonded to four Se2- atoms to form SnSe4 tetrahedra that share a cornercorner with one BaSe7 pentagonal bipyramid and edges with three equivalent BaSe7 pentagonal bipyramids. There are a spread of Sn–Se bond distances ranging from 2.55–2.59 Å. There are four inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 5-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 1-coordinate geometry to four Ba2+ and one Sn4+ atom.