Materials Data on K2RbBiSe3 by Materials Project

Abstract

RbK2BiSe3 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. Rb1+ is bonded to six equivalent Se2- atoms to form RbSe6 octahedra that share corners with six equivalent RbSe6 octahedra, corners with six KSe6 octahedra, edges with six KSe6 octahedra, and faces with two KSe6 octahedra. The corner-sharing octahedra tilt angles range from 37–58°. There are three shorter (3.61 Å) and three longer (3.66 Å) Rb–Se bond lengths. There are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded to six equivalent Se2- atoms to form distorted KSe6 octahedra that share corners with three equivalent RbSe6 octahedra, corners with nine KSe6 octahedra, edges with three equivalent RbSe6 octahedra, a faceface with one RbSe6 octahedra, and faces with three equivalent KSe6 octahedra. The corner-sharing octahedra tilt angles range from 28–45°. There are three shorter (3.36 Å) and three longer (3.54 Å) K–Se bond lengths. In the second K1+ site, K1+ is bonded to six equivalent Se2- atoms to form distorted KSe6 octahedra that share corners with three equivalent RbSe6 octahedra, corners with nine KSe6 octahedra, edges with three equivalent RbSe6 octahedra, a faceface with one RbSe6 octahedra, and faces with three equivalent KSe6 octahedra. The corner-sharing octahedra tilt angles range from 28–43°. There are three shorter (3.37 Å) and three longer (3.53 Å) K–Se bond lengths. Bi3+ is bonded in a trigonal non-coplanar geometry to three equivalent Se2- atoms. All Bi–Se bond lengths are 2.70 Å. Se2- is bonded to two equivalent Rb1+, four K1+, and one Bi3+ atom to form a mixture of distorted face, edge, and corner-sharing SeK4Rb2Bi pentagonal bipyramids.