Materials Data on Co9S8 by Materials Project

Abstract

Co9S8 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are two inequivalent Co+1.78+ sites. In the first Co+1.78+ site, Co+1.78+ is bonded to four S2- atoms to form CoS4 tetrahedra that share corners with three equivalent CoS6 octahedra, corners with six equivalent CoS4 tetrahedra, and edges with three equivalent CoS4 tetrahedra. The corner-sharing octahedral tilt angles are 53°. There are one shorter (2.10 Å) and three longer (2.20 Å) Co–S bond lengths. In the second Co+1.78+ site, Co+1.78+ is bonded to six equivalent S2- atoms to form corner-sharing CoS6 octahedra. All Co–S bond lengths are 2.34 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a tetrahedral geometry to four equivalent Co+1.78+ atoms. In the second S2- site, S2- is bonded in a 5-coordinate geometry to five Co+1.78+ atoms.