Materials Data on Cs3AsSe4 by Materials Project

Abstract

Cs3AsSe4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.63–3.87 Å. In the second Cs1+ site, Cs1+ is bonded in a 5-coordinate geometry to five Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.66–3.80 Å. As5+ is bonded in a tetrahedral geometry to four Se2- atoms. There are three shorter (2.36 Å) and one longer (2.37 Å) As–Se bond lengths. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to five Cs1+ and one As5+ atom to form SeCs5As octahedra that share corners with five equivalent SeCs6As pentagonal bipyramids, edges with two equivalent SeCs5As octahedra, and faces with two equivalent SeCs6As pentagonal bipyramids. In the second Se2- site, Se2- is bonded to six Cs1+ and one As5+ atom to form distorted SeCs6As pentagonal bipyramids that share corners with five equivalent SeCs5As octahedra, corners with two equivalent SeCs6As pentagonal bipyramids, edges with two equivalent SeCs6As pentagonal bipyramids, and faces with two equivalent SeCs5As octahedra. The corner-sharing octahedra tilt angles range from 12–49°. In the third Se2- site, Se2- is bonded in a 1-coordinate geometry to four Cs1+ and one As5+ atom.