Materials Data on Zr4Co4Si7 by Materials Project

Abstract

Zr4Co4Si7 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are two inequivalent Zr2+ sites. In the first Zr2+ site, Zr2+ is bonded to seven Si+1.71- atoms to form ZrSi7 pentagonal bipyramids that share corners with eight equivalent CoSi6 octahedra, corners with eight ZrSi7 pentagonal bipyramids, edges with three equivalent ZrSi7 pentagonal bipyramids, faces with four equivalent CoSi6 octahedra, and faces with six ZrSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 44–52°. There are a spread of Zr–Si bond distances ranging from 2.76–2.87 Å. In the second Zr2+ site, Zr2+ is bonded to seven Si+1.71- atoms to form ZrSi7 pentagonal bipyramids that share corners with eight equivalent CoSi6 octahedra, corners with eight ZrSi7 pentagonal bipyramids, an edgeedge with one ZrSi7 pentagonal bipyramid, faces with four equivalent CoSi6 octahedra, and faces with six ZrSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 42–53°. There are a spread of Zr–Si bond distances ranging from 2.73–2.89 Å. Co1+ is bonded to six Si+1.71- atoms to form distorted CoSi6 octahedra that share corners with six equivalent CoSi6 octahedra, corners with eight ZrSi7 pentagonal bipyramids, edges with three equivalent CoSi6 octahedra, faces with two equivalent CoSi6 octahedra, and faces with four ZrSi7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 31–35°. There are four shorter (2.38 Å) and two longer (2.40 Å) Co–Si bond lengths. There are four inequivalent Si+1.71- sites. In the first Si+1.71- site, Si+1.71- is bonded in a 6-coordinate geometry to one Zr2+, four equivalent Co1+, and one Si+1.71- atom. The Si–Si bond length is 2.38 Å. In the second Si+1.71- site, Si+1.71- is bonded in a 10-coordinate geometry to eight Zr2+ and two equivalent Si+1.71- atoms. There are one shorter (2.53 Å) and one longer (2.55 Å) Si–Si bond lengths. In the third Si+1.71- site, Si+1.71- is bonded in a 9-coordinate geometry to five Zr2+ and four equivalent Co1+ atoms. In the fourth Si+1.71- site, Si+1.71- is bonded in a 12-coordinate geometry to four Zr2+ and four equivalent Co1+ atoms.