Materials Data on CoSi4Ni3 by Materials Project

Abstract

CoNi3Si4 crystallizes in the monoclinic Pm space group. The structure is three-dimensional. Co2+ is bonded to six Si2- atoms to form distorted CoSi6 pentagonal pyramids that share corners with twelve NiSi6 octahedra, edges with two equivalent CoSi6 pentagonal pyramids, edges with four equivalent NiSi6 pentagonal pyramids, and faces with two equivalent NiSi6 octahedra. The corner-sharing octahedra tilt angles range from 45–59°. There are a spread of Co–Si bond distances ranging from 2.27–2.35 Å. There are three inequivalent Ni2+ sites. In the first Ni2+ site, Ni2+ is bonded to six Si2- atoms to form distorted NiSi6 octahedra that share corners with four equivalent CoSi6 pentagonal pyramids, corners with eight equivalent NiSi6 pentagonal pyramids, edges with six NiSi6 octahedra, and faces with two equivalent CoSi6 pentagonal pyramids. There are a spread of Ni–Si bond distances ranging from 2.28–2.39 Å. In the second Ni2+ site, Ni2+ is bonded to six Si2- atoms to form distorted NiSi6 pentagonal pyramids that share corners with twelve NiSi6 octahedra, edges with two equivalent NiSi6 pentagonal pyramids, edges with four equivalent CoSi6 pentagonal pyramids, and faces with two equivalent NiSi6 octahedra. The corner-sharing octahedra tilt angles range from 45–60°. There are a spread of Ni–Si bond distances ranging from 2.27–2.39 Å. In the third Ni2+ site, Ni2+ is bonded to six Si2- atoms to form distorted NiSi6 octahedra that share corners with four equivalent NiSi6 pentagonal pyramids, corners with eight equivalent CoSi6 pentagonal pyramids, edges with six NiSi6 octahedra, and faces with two equivalent NiSi6 pentagonal pyramids. There are a spread of Ni–Si bond distances ranging from 2.31–2.42 Å. There are four inequivalent Si2- sites. In the first Si2- site, Si2- is bonded in a 8-coordinate geometry to one Co2+, five Ni2+, and two equivalent Si2- atoms. Both Si–Si bond lengths are 2.60 Å. In the second Si2- site, Si2- is bonded in a 8-coordinate geometry to one Co2+, five Ni2+, and two equivalent Si2- atoms. Both Si–Si bond lengths are 2.68 Å. In the third Si2- site, Si2- is bonded in a 8-coordinate geometry to two equivalent Co2+, four Ni2+, and two equivalent Si2- atoms. In the fourth Si2- site, Si2- is bonded in a 8-coordinate geometry to two equivalent Co2+, four Ni2+, and two equivalent Si2- atoms.