Materials Data on Cs2PSe5 by Materials Project

Cs2PSe5 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent Cs1+ sites. In the first Cs1+ site, Cs1+ is bonded to eight Se+1.40- atoms to form distorted CsSe8 hexagonal bipyramids that share corners with two equivalent CsSe8 hexagonal bipyramids, corners with two equivalent PSe4 tetrahedra, edges with two equivalent CsSe8 hexagonal bipyramids, edges with two equivalent PSe4 tetrahedra, and a faceface with one CsSe8 hexagonal bipyramid. There are a spread of Cs–Se bond distances ranging from 3.76–4.08 Å. In the second Cs1+ site, Cs1+ is bonded in a 9-coordinate geometry to nine Se+1.40- atoms. There are a spread of Cs–Se bond distances ranging from 3.71–4.18 Å. P5+ is bonded to four Se+1.40- atoms to form PSe4 tetrahedra that share corners with two equivalent CsSe8 hexagonal bipyramids and edges with two equivalent CsSe8 hexagonal bipyramids. There are a spread of P–Se bond distances ranging from 2.18–2.35 Å. There are five inequivalent Se+1.40- sites. In the first Se+1.40- site, Se+1.40- is bonded in a distorted single-bond geometry to four Cs1+ and one P5+ atom. In the second Se+1.40- site, Se+1.40- is bonded in a 1-coordinate geometry to two equivalent Cs1+, one P5+, and one Se+1.40- atom. The Se–Se bond length is 2.35 Å. In the third Se+1.40- site, Se+1.40- is bonded in a 1-coordinate geometry to four Cs1+ and one P5+ atom. In the fourth Se+1.40- site, Se+1.40- is bonded in a 6-coordinate geometry to two equivalent Cs1+ and two Se+1.40- atoms. The Se–Se bond length is 2.48 Å. In the fifth Se+1.40- site, Se+1.40- is bonded in a 1-coordinate geometry to five Cs1+ and one P5+ atom.