Materials Data on CoNi5S8 by Materials Project
CoNi5S8 is Spinel-like structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Co4+ is bonded to four equivalent S2- atoms to form CoS4 tetrahedra that share corners with twelve equivalent NiS6 octahedra. The corner-sharing octahedral tilt angles are 57°. All Co–S bond lengths are 2.15 Å. There are two inequivalent Ni+2.40+ sites. In the first Ni+2.40+ site, Ni+2.40+ is bonded to six S2- atoms to form NiS6 octahedra that share corners with three equivalent CoS4 tetrahedra, corners with three equivalent NiS4 tetrahedra, and edges with six equivalent NiS6 octahedra. There are three shorter (2.28 Å) and three longer (2.29 Å) Ni–S bond lengths. In the second Ni+2.40+ site, Ni+2.40+ is bonded to four equivalent S2- atoms to form corner-sharing NiS4 tetrahedra. The corner-sharing octahedral tilt angles are 58°. All Ni–S bond lengths are 2.17 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to four Ni+2.40+ atoms to form a mixture of distorted edge and corner-sharing SNi4 trigonal pyramids. In the second S2- site, S2- is bonded in a distorted rectangular see-saw-like geometry to one Co4+ and three equivalent Ni+2.40+ atoms.