Materials Data on Cs2GeSe3 by Materials Project

Abstract

Cs2GeSe3 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to seven Se2- atoms to form CsSe7 pentagonal bipyramids that share corners with four CsSe7 pentagonal bipyramids, corners with three equivalent GeSe4 tetrahedra, edges with eight CsSe7 pentagonal bipyramids, edges with three equivalent GeSe4 tetrahedra, and faces with two equivalent CsSe7 pentagonal bipyramids. There are a spread of Cs–Se bond distances ranging from 3.63–3.88 Å. In the second Cs1+ site, Cs1+ is bonded to seven Se2- atoms to form distorted CsSe7 pentagonal bipyramids that share corners with four CsSe7 pentagonal bipyramids, corners with five equivalent GeSe4 tetrahedra, edges with eight CsSe7 pentagonal bipyramids, edges with two equivalent GeSe4 tetrahedra, and faces with two equivalent CsSe7 pentagonal bipyramids. There are a spread of Cs–Se bond distances ranging from 3.68–4.22 Å. Ge4+ is bonded to four Se2- atoms to form GeSe4 tetrahedra that share corners with eight CsSe7 pentagonal bipyramids, edges with five CsSe7 pentagonal bipyramids, and an edgeedge with one GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.33–2.47 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to five Cs1+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing SeCs5Ge octahedra. The corner-sharing octahedra tilt angles range from 3–77°. In the second Se2- site, Se2- is bonded to five Cs1+ and one Ge4+ atom to form a mixture of distorted edge and corner-sharing SeCs5Ge octahedra. The corner-sharing octahedra tilt angles range from 3–77°. In the third Se2- site, Se2- is bonded in a 2-coordinate geometry to four Cs1+ and two equivalent Ge4+ atoms.