Materials Data on Cs3GeAsSe5 by Materials Project

Abstract

Cs3GeAsSe5 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are three inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.62–4.25 Å. In the second 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 3.65–4.20 Å. In the third Cs1+ site, Cs1+ is bonded to seven Se2- atoms to form distorted CsSe7 pentagonal bipyramids that share corners with two equivalent GeSe4 tetrahedra, edges with two equivalent CsSe7 pentagonal bipyramids, and edges with two equivalent GeSe4 tetrahedra. There are a spread of Cs–Se bond distances ranging from 3.66–3.94 Å. Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share corners with two equivalent CsSe7 pentagonal bipyramids and edges with two equivalent CsSe7 pentagonal bipyramids. There are two shorter (2.33 Å) and two longer (2.48 Å) Ge–Se bond lengths. 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 2.35–2.52 Å. There are five inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 1-coordinate geometry to four Cs1+ and one Ge4+ atom. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to four Cs1+, one Ge4+, and one As3+ atom. In the third Se2- site, Se2- is bonded in a 1-coordinate geometry to five Cs1+ and one Ge4+ atom. In the fourth Se2- site, Se2- is bonded in a 6-coordinate geometry to four Cs1+, one Ge4+, and one As3+ atom. In the fifth Se2- site, Se2- is bonded in a 6-coordinate geometry to five Cs1+ and one As3+ atom.