Materials Data on AlCo2Si by Materials Project

Abstract

Co2AlSi crystallizes in the orthorhombic Immm space group. The structure is three-dimensional. there are two inequivalent Co sites. In the first Co site, Co is bonded to six equivalent Co, one Al, and one Si atom to form distorted CoAlCo6Si hexagonal bipyramids that share corners with eight equivalent CoAlCo6Si hexagonal bipyramids, edges with six equivalent AlAl2Co2Si4 hexagonal bipyramids, edges with six equivalent SiAl4Co2Si2 hexagonal bipyramids, and edges with twelve equivalent CoAlCo6Si hexagonal bipyramids. There are four shorter (2.56 Å) and two longer (2.58 Å) Co–Co bond lengths. The Co–Al bond length is 2.60 Å. The Co–Si bond length is 2.20 Å. In the second Co site, Co is bonded to six Co, one Al, and one Si atom to form distorted CoAlCo6Si hexagonal bipyramids that share corners with eight CoAlCo6Si hexagonal bipyramids, edges with six equivalent AlAl2Co2Si4 hexagonal bipyramids, edges with six equivalent SiAl4Co2Si2 hexagonal bipyramids, and edges with twelve CoAlCo6Si hexagonal bipyramids. There are four shorter (2.56 Å) and two longer (2.58 Å) Co–Co bond lengths. The Co–Al bond length is 2.60 Å. The Co–Si bond length is 2.20 Å. Al is bonded to two equivalent Co, two equivalent Al, and four equivalent Si atoms to form distorted AlAl2Co2Si4 hexagonal bipyramids that share corners with two equivalent SiAl4Co2Si2 hexagonal bipyramids, corners with six equivalent AlAl2Co2Si4 hexagonal bipyramids, edges with four equivalent AlAl2Co2Si4 hexagonal bipyramids, edges with eight equivalent SiAl4Co2Si2 hexagonal bipyramids, and edges with twelve CoAlCo6Si hexagonal bipyramids. Both Al–Al bond lengths are 2.58 Å. All Al–Si bond lengths are 2.52 Å. Si is bonded to two equivalent Co, four equivalent Al, and two equivalent Si atoms to form distorted SiAl4Co2Si2 hexagonal bipyramids that share corners with two equivalent AlAl2Co2Si4 hexagonal bipyramids, corners with six equivalent SiAl4Co2Si2 hexagonal bipyramids, edges with four equivalent SiAl4Co2Si2 hexagonal bipyramids, edges with eight equivalent AlAl2Co2Si4 hexagonal bipyramids, and edges with twelve CoAlCo6Si hexagonal bipyramids. Both Si–Si bond lengths are 2.58 Å.