Materials Data on Ta3Co8Si by Materials Project

Abstract

Ta3Co8Si crystallizes in the trigonal P3m1 space group. The structure is three-dimensional. there are three inequivalent Ta sites. In the first Ta site, Ta is bonded in a 9-coordinate geometry to one Ta, twelve Co, and three equivalent Si atoms. The Ta–Ta bond length is 2.86 Å. There are a spread of Ta–Co bond distances ranging from 2.72–2.79 Å. All Ta–Si bond lengths are 2.84 Å. In the second Ta site, Ta is bonded in a 12-coordinate geometry to four Ta and twelve Co atoms. All Ta–Ta bond lengths are 3.01 Å. There are a spread of Ta–Co bond distances ranging from 2.75–2.81 Å. In the third Ta site, Ta is bonded in a 10-coordinate geometry to three equivalent Ta, twelve Co, and one Si atom. There are a spread of Ta–Co bond distances ranging from 2.66–2.96 Å. The Ta–Si bond length is 2.81 Å. There are four inequivalent Co sites. In the first Co site, Co is bonded to three equivalent Ta, six Co, and three equivalent Si atoms to form CoTa3Co6Si3 cuboctahedra that share corners with twelve CoTa4Co6Si2 cuboctahedra, edges with six equivalent CoTa3Co6Si3 cuboctahedra, and faces with twenty CoTa6Co6 cuboctahedra. There are three shorter (2.35 Å) and three longer (2.37 Å) Co–Co bond lengths. All Co–Si bond lengths are 2.75 Å. In the second Co site, Co is bonded to six Ta and six Co atoms to form CoTa6Co6 cuboctahedra that share corners with twelve CoTa4Co6Si2 cuboctahedra, edges with six equivalent CoTa6Co6 cuboctahedra, and faces with twenty CoTa3Co6Si3 cuboctahedra. There are three shorter (2.36 Å) and three longer (2.39 Å) Co–Co bond lengths. In the third Co site, Co is bonded to four Ta, six Co, and two equivalent Si atoms to form distorted CoTa4Co6Si2 cuboctahedra that share corners with eighteen CoTa3Co6Si3 cuboctahedra, edges with six CoTa5Co6Si cuboctahedra, and faces with eighteen CoTa3Co6Si3 cuboctahedra. There are two shorter (2.35 Å) and two longer (2.39 Å) Co–Co bond lengths. Both Co–Si bond lengths are 2.86 Å. In the fourth Co site, Co is bonded to five Ta, six Co, and one Si atom to form CoTa5Co6Si cuboctahedra that share corners with eighteen CoTa3Co6Si3 cuboctahedra, edges with six CoTa5Co6Si cuboctahedra, and faces with eighteen CoTa3Co6Si3 cuboctahedra. There are two shorter (2.34 Å) and two longer (2.40 Å) Co–Co bond lengths. The Co–Si bond length is 2.60 Å. Si is bonded in a 4-coordinate geometry to four Ta and twelve Co atoms.