Materials Data on Rb9Co2S7 by Materials Project

Abstract

Rb9Co2S7 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are five inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to five S2- atoms to form distorted RbS5 square pyramids that share a cornercorner with one RbS6 octahedra, corners with six equivalent RbS5 square pyramids, a cornercorner with one CoS4 tetrahedra, an edgeedge with one CoS4 tetrahedra, and a faceface with one RbS6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Rb–S bond distances ranging from 3.16–3.36 Å. In the second Rb1+ site, Rb1+ is bonded in a 6-coordinate geometry to six S2- atoms. There are three shorter (3.47 Å) and three longer (3.48 Å) Rb–S bond lengths. In the third Rb1+ site, Rb1+ is bonded to six S2- atoms to form distorted RbS6 octahedra that share corners with three equivalent RbS5 square pyramids, corners with three equivalent CoS4 tetrahedra, and faces with three equivalent RbS5 square pyramids. There are three shorter (3.43 Å) and three longer (3.61 Å) Rb–S bond lengths. In the fourth Rb1+ site, Rb1+ is bonded in a 5-coordinate geometry to five S2- atoms. There are a spread of Rb–S bond distances ranging from 3.46–3.60 Å. In the fifth Rb1+ site, Rb1+ is bonded in a distorted T-shaped geometry to three equivalent S2- atoms. All Rb–S bond lengths are 3.36 Å. There are two inequivalent Co+2.50+ sites. In the first Co+2.50+ site, Co+2.50+ is bonded to four S2- atoms to form CoS4 tetrahedra that share corners with three equivalent RbS6 octahedra, corners with three equivalent RbS5 square pyramids, and edges with three equivalent RbS5 square pyramids. The corner-sharing octahedral tilt angles are 42°. There are three shorter (2.32 Å) and one longer (2.35 Å) Co–S bond lengths. In the second Co+2.50+ site, Co+2.50+ is bonded in a trigonal planar geometry to three equivalent S2- atoms. All Co–S bond lengths are 2.19 Å. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a 1-coordinate geometry to seven Rb1+ and one Co+2.50+ atom. In the second S2- site, S2- is bonded in a 1-coordinate geometry to six Rb1+ and one Co+2.50+ atom. In the third S2- site, S2- is bonded in a 7-coordinate geometry to six Rb1+ and one Co+2.50+ atom.