Materials Data on Co(NiS2)2 by Materials Project

Abstract

CoNi2S4 is Spinel-like structured and crystallizes in the orthorhombic Imma space group. The structure is three-dimensional. Co4+ is bonded to six S2- atoms to form CoS6 octahedra that share corners with six equivalent NiS4 tetrahedra, edges with two equivalent CoS6 octahedra, and edges with four equivalent NiS6 octahedra. There are two shorter (2.24 Å) and four longer (2.25 Å) Co–S bond lengths. There are two inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to four S2- atoms to form NiS4 tetrahedra that share corners with six equivalent CoS6 octahedra and corners with six equivalent NiS6 octahedra. The corner-sharing octahedra tilt angles range from 57–59°. There are two shorter (2.17 Å) and two longer (2.19 Å) Ni–S bond lengths. In the second Ni2+ site, Ni2+ is bonded to six S2- atoms to form NiS6 octahedra that share corners with six equivalent NiS4 tetrahedra, edges with two equivalent NiS6 octahedra, and edges with four equivalent CoS6 octahedra. There are four shorter (2.27 Å) and two longer (2.28 Å) Ni–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded to one Co4+ and three Ni2+ atoms to form a mixture of distorted edge and corner-sharing SCoNi3 trigonal pyramids. In the second S2- site, S2- is bonded to two equivalent Co4+ and two Ni2+ atoms to form a mixture of distorted edge and corner-sharing SCo2Ni2 trigonal pyramids.