Materials Data on Ba2As2Se5 by Materials Project
Ba2As2Se5 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four 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 3.34–3.81 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 3.33–3.57 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 3.34–3.61 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 3.32–3.71 Å. There are four inequivalent As3+ sites. In the first As3+ site, As3+ is bonded in a trigonal non-coplanar geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.43–2.55 Å. In the second As3+ site, As3+ is bonded in a distorted trigonal non-coplanar geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.41–2.44 Å. In the third As3+ site, As3+ is bonded in a 3-coordinate geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.41–2.55 Å. In the fourth As3+ site, As3+ is bonded in a distorted trigonal non-coplanar geometry to three Se2- atoms. There are a spread of As–Se bond distances ranging from 2.39–2.46 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to three Ba2+ and one As3+ atom. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to three Ba2+ and one As3+ atom. In the third Se2- site, Se2- is bonded in a 4-coordinate geometry to two Ba2+ and two As3+ atoms. In the fourth Se2- site, Se2- is bonded in a 4-coordinate geometry to two equivalent Ba2+ and two As3+ atoms. In the fifth Se2- site, Se2- is bonded to four Ba2+ and one As3+ atom to form a mixture of distorted corner and edge-sharing SeBa4As square pyramids. In the sixth Se2- site, Se2- is bonded to four Ba2+ and one As3+ atom to form a mixture of distorted corner, edge, and face-sharing SeBa4As square pyramids. In the seventh Se2- site, Se2- is bonded to four Ba2+ and one As3+ atom to form a mixture of distorted corner and face-sharing SeBa4As square pyramids. In the eighth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ba2+ and one As3+ atom. In the ninth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ba2+ and one As3+ atom. In the tenth Se2- site, Se2- is bonded in a 5-coordinate geometry to four Ba2+ and one As3+ atom.