Materials Data on Rb2Cd3Se4 by Materials Project

Abstract

Rb2Cd3Se4 crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to seven Se2- atoms to form distorted RbSe7 pentagonal bipyramids that share corners with two equivalent RbSe7 pentagonal bipyramids, corners with eleven CdSe4 tetrahedra, edges with two equivalent RbSe6 octahedra, edges with two equivalent RbSe7 pentagonal bipyramids, edges with five CdSe4 tetrahedra, and faces with two equivalent RbSe6 octahedra. There are a spread of Rb–Se bond distances ranging from 3.62–3.92 Å. In the second Rb1+ site, Rb1+ is bonded to six Se2- atoms to form distorted RbSe6 octahedra that share corners with ten CdSe4 tetrahedra, edges with two equivalent RbSe6 octahedra, edges with two equivalent RbSe7 pentagonal bipyramids, edges with four CdSe4 tetrahedra, and faces with two equivalent RbSe7 pentagonal bipyramids. There are a spread of Rb–Se bond distances ranging from 3.51–3.71 Å. There are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with four equivalent RbSe6 octahedra, corners with three equivalent RbSe7 pentagonal bipyramids, corners with four CdSe4 tetrahedra, an edgeedge with one RbSe6 octahedra, edges with two equivalent RbSe7 pentagonal bipyramids, and edges with two CdSe4 tetrahedra. The corner-sharing octahedra tilt angles range from 8–92°. There are a spread of Cd–Se bond distances ranging from 2.66–2.81 Å. In the second Cd2+ site, Cd2+ is bonded to four Se2- atoms to form distorted CdSe4 tetrahedra that share corners with two equivalent RbSe6 octahedra, corners with five equivalent RbSe7 pentagonal bipyramids, corners with four equivalent CdSe4 tetrahedra, edges with two equivalent RbSe6 octahedra, an edgeedge with one RbSe7 pentagonal bipyramid, and edges with two equivalent CdSe4 tetrahedra. The corner-sharing octahedral tilt angles are 57°. There are a spread of Cd–Se bond distances ranging from 2.64–2.79 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to three Rb1+ and three Cd2+ atoms. In the second Se2- site, Se2- is bonded to three Rb1+ and three Cd2+ atoms to form a mixture of distorted edge and corner-sharing SeRb3Cd3 octahedra. The corner-sharing octahedra tilt angles range from 0–53°. In the third Se2- site, Se2- is bonded in a 7-coordinate geometry to four Rb1+ and three Cd2+ atoms.