Materials Data on Cs2MgGe3Se8 by Materials Project

Abstract

Cs2MgGe3Se8 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded in a 9-coordinate geometry to nine Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.70–4.10 Å. In the second 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 3.68–4.10 Å. Mg2+ is bonded to four Se2- atoms to form MgSe4 tetrahedra that share corners with four GeSe4 tetrahedra. There are a spread of Mg–Se bond distances ranging from 2.60–2.62 Å. There are three inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share a cornercorner with one MgSe4 tetrahedra, a cornercorner with one GeSe4 tetrahedra, and an edgeedge with one GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.34–2.44 Å. In the second Ge4+ site, Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share a cornercorner with one MgSe4 tetrahedra, a cornercorner with one GeSe4 tetrahedra, and an edgeedge with one GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.34–2.44 Å. In the third Ge4+ site, Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share corners with two equivalent MgSe4 tetrahedra and corners with two GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.35–2.46 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a distorted water-like geometry to one Cs1+, one Mg2+, and one Ge4+ atom. In the second Se2- site, Se2- is bonded in a 2-coordinate geometry to two Cs1+, one Mg2+, and one Ge4+ atom. In the third Se2- site, Se2- is bonded in a 2-coordinate geometry to two equivalent Cs1+ and two Ge4+ atoms. In the fourth Se2- site, Se2- is bonded in a 2-coordinate geometry to three equivalent Cs1+ and two Ge4+ atoms. In the fifth Se2- site, Se2- is bonded in a distorted water-like geometry to two Cs1+ and two Ge4+ atoms. In the sixth Se2- site, Se2- is bonded in a distorted water-like geometry to two Cs1+ and two Ge4+ atoms. In the seventh Se2- site, Se2- is bonded in a 2-coordinate geometry to two Cs1+, one Mg2+, and one Ge4+ atom. In the eighth Se2- site, Se2- is bonded in a distorted water-like geometry to three Cs1+, one Mg2+, and one Ge4+ atom.