Materials Data on Sm(AlAu)2 by Materials Project

Sm(AuAl)2 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Sm is bonded in a 8-coordinate geometry to eight Au and eight Al atoms. There are four shorter (3.38 Å) and four longer (3.39 Å) Sm–Au bond lengths. There are four shorter (3.37 Å) and four longer (3.43 Å) Sm–Al bond lengths. There are two inequivalent Au sites. In the first Au site, Au is bonded to four equivalent Sm and four equivalent Al atoms to form distorted AuSm4Al4 tetrahedra that share corners with twelve equivalent AlSm4Au4 tetrahedra, edges with two equivalent AlSm4Au4 tetrahedra, edges with four equivalent AuSm4Al4 tetrahedra, and faces with four equivalent AuSm4Al4 tetrahedra. All Au–Al bond lengths are 2.60 Å. In the second Au site, Au is bonded in a 5-coordinate geometry to four equivalent Sm and five Al atoms. There are one shorter (2.49 Å) and four longer (2.59 Å) Au–Al bond lengths. There are two inequivalent Al sites. In the first Al site, Al is bonded to four equivalent Sm and four equivalent Au atoms to form distorted AlSm4Au4 tetrahedra that share corners with twelve equivalent AuSm4Al4 tetrahedra, edges with two equivalent AuSm4Al4 tetrahedra, edges with four equivalent AlSm4Au4 tetrahedra, and faces with four equivalent AlSm4Au4 tetrahedra. In the second Al site, Al is bonded in a 5-coordinate geometry to four equivalent Sm and five Au atoms.