Materials Data on CsGd2Ag3Se5 by Materials Project

Abstract

CsGd2Ag3Se5 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Cs1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.64–3.81 Å. Gd3+ is bonded to six Se2- atoms to form GdSe6 octahedra that share a cornercorner with one GdSe6 octahedra, corners with four equivalent AgSe4 tetrahedra, edges with four equivalent GdSe6 octahedra, and edges with five AgSe4 tetrahedra. The corner-sharing octahedral tilt angles are 37°. There are a spread of Gd–Se bond distances ranging from 2.91–2.98 Å. There are two inequivalent Ag1+ sites. In the first Ag1+ site, Ag1+ is bonded to four Se2- atoms to form AgSe4 tetrahedra that share corners with six AgSe4 tetrahedra and edges with four equivalent GdSe6 octahedra. There are two shorter (2.65 Å) and two longer (2.74 Å) Ag–Se bond lengths. In the second Ag1+ site, Ag1+ is bonded to four Se2- atoms to form distorted AgSe4 tetrahedra that share corners with four equivalent GdSe6 octahedra, corners with four AgSe4 tetrahedra, edges with three equivalent GdSe6 octahedra, and an edgeedge with one AgSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 8–59°. There are a spread of Ag–Se bond distances ranging from 2.71–2.80 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 7-coordinate geometry to two equivalent Cs1+, two equivalent Gd3+, and three Ag1+ atoms. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent Cs1+, two equivalent Gd3+, and two equivalent Ag1+ atoms. In the third Se2- site, Se2- is bonded to one Cs1+, three equivalent Gd3+, and two equivalent Ag1+ atoms to form a mixture of distorted corner and edge-sharing SeCsGd3Ag2 octahedra. The corner-sharing octahedral tilt angles are 60°.