Materials Data on Sr(AlAu)2 by Materials Project

Abstract

SrAu2Al2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Sr is bonded in a 8-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.45 Å) and four longer (3.47 Å) Sr–Au bond lengths. There are four shorter (3.46 Å) and four longer (3.48 Å) Sr–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to four equivalent Sr and four equivalent Al atoms to form distorted AuSr4Al4 tetrahedra that share corners with twelve equivalent AlSr4Au4 tetrahedra, edges with two equivalent AlSr4Au4 tetrahedra, edges with four equivalent AuSr4Al4 tetrahedra, and faces with four equivalent AuSr4Al4 tetrahedra. All Au–Al bond lengths are 2.62 Å. In the second Au site, Au is bonded in a 9-coordinate geometry to four equivalent Sr and five Al atoms. There are one shorter (2.58 Å) and four longer (2.65 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Sr and four equivalent Au atoms to form distorted AlSr4Au4 tetrahedra that share corners with twelve equivalent AuSr4Al4 tetrahedra, edges with two equivalent AuSr4Al4 tetrahedra, edges with four equivalent AlSr4Au4 tetrahedra, and faces with four equivalent AlSr4Au4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent Sr and five Au atoms.