Materials Data on Th2Al8Si2Au5 by Materials Project

Abstract

Th2Au5Al8Si2 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Th is bonded in a 10-coordinate geometry to four equivalent Au, four Al, and six equivalent Si atoms. All Th–Au bond lengths are 3.30 Å. All Th–Al bond lengths are 3.48 Å. There are two shorter (3.14 Å) and four longer (3.26 Å) Th–Si bond lengths. There are three inequivalent Au sites. In the first Au site, Au is bonded in a 9-coordinate geometry to four equivalent Th, four Al, and one Si atom. All Au–Al bond lengths are 2.59 Å. The Au–Si bond length is 2.46 Å. In the second Au site, Au is bonded in a body-centered cubic geometry to eight Al atoms. All Au–Al bond lengths are 2.62 Å. In the third Au site, Au is bonded in a body-centered cubic geometry to eight Al atoms. There are six shorter (2.61 Å) and two longer (2.62 Å) Au–Al bond lengths. There are four inequivalent Al sites. In the first Al site, Al is bonded to two equivalent Th and four Au atoms to form a mixture of edge, face, and corner-sharing AlTh2Au4 tetrahedra. In the second Al site, Al is bonded to two equivalent Th and four Au atoms to form AlTh2Au4 tetrahedra that share corners with eight AlTh2Au4 tetrahedra, edges with three AlAu4 tetrahedra, and faces with four equivalent AlTh2Au4 tetrahedra. In the third Al site, Al is bonded to four Au atoms to form a mixture of edge and corner-sharing AlAu4 tetrahedra. In the fourth Al site, Al is bonded to four Au atoms to form a mixture of edge and corner-sharing AlAu4 tetrahedra. Si is bonded in a distorted single-bond geometry to six equivalent Th and one Au atom.