Materials Data on Co5As2 by Materials Project

Abstract

Co5As2 crystallizes in the hexagonal P6_3cm space group. The structure is three-dimensional. there are six inequivalent Co+1.20+ sites. In the first Co+1.20+ site, Co+1.20+ is bonded to four As3- atoms to form CoAs4 tetrahedra that share corners with three equivalent CoAs5 square pyramids, corners with twelve CoAs4 tetrahedra, edges with three equivalent CoAs5 square pyramids, and edges with three equivalent CoAs4 tetrahedra. There are three shorter (2.39 Å) and one longer (2.50 Å) Co–As bond lengths. In the second Co+1.20+ site, Co+1.20+ is bonded to four As3- atoms to form CoAs4 tetrahedra that share corners with six equivalent CoAs5 square pyramids, corners with twelve CoAs4 tetrahedra, edges with three equivalent CoAs5 square pyramids, and edges with three equivalent CoAs4 tetrahedra. There are three shorter (2.44 Å) and one longer (2.53 Å) Co–As bond lengths. In the third Co+1.20+ site, Co+1.20+ is bonded in a distorted trigonal non-coplanar geometry to three As3- atoms. There are two shorter (2.41 Å) and one longer (2.42 Å) Co–As bond lengths. In the fourth Co+1.20+ site, Co+1.20+ is bonded to four As3- atoms to form CoAs4 tetrahedra that share corners with seven equivalent CoAs5 square pyramids, corners with twelve CoAs4 tetrahedra, an edgeedge with one CoAs5 square pyramid, and edges with five CoAs4 tetrahedra. There are a spread of Co–As bond distances ranging from 2.35–2.57 Å. In the fifth Co+1.20+ site, Co+1.20+ is bonded to four As3- atoms to form CoAs4 tetrahedra that share corners with two equivalent CoAs5 square pyramids, corners with fourteen CoAs4 tetrahedra, edges with two equivalent CoAs5 square pyramids, edges with four CoAs4 tetrahedra, and a faceface with one CoAs5 square pyramid. There are a spread of Co–As bond distances ranging from 2.29–2.40 Å. In the sixth Co+1.20+ site, Co+1.20+ is bonded to five As3- atoms to form distorted CoAs5 square pyramids that share corners with two equivalent CoAs5 square pyramids, corners with fourteen CoAs4 tetrahedra, edges with four equivalent CoAs5 square pyramids, edges with six CoAs4 tetrahedra, and a faceface with one CoAs4 tetrahedra. There are a spread of Co–As bond distances ranging from 2.35–2.71 Å. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 10-coordinate geometry to ten Co+1.20+ atoms. In the second As3- site, As3- is bonded in a 10-coordinate geometry to ten Co+1.20+ atoms. In the third As3- site, As3- is bonded in a 10-coordinate geometry to ten Co+1.20+ atoms.