Materials Data on Mg(AlSn)2 by Materials Project

Abstract

Mg(AlSn)2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Mg is bonded to six equivalent Sn atoms to form MgSn6 octahedra that share corners with twelve equivalent AlSn4 tetrahedra, edges with six equivalent MgSn6 octahedra, and edges with six equivalent AlSn4 tetrahedra. All Mg–Sn bond lengths are 3.08 Å. Al is bonded to four equivalent Sn atoms to form AlSn4 tetrahedra that share corners with six equivalent MgSn6 octahedra, corners with six equivalent AlSn4 tetrahedra, edges with three equivalent MgSn6 octahedra, and edges with three equivalent AlSn4 tetrahedra. The corner-sharing octahedra tilt angles range from 11–57°. There are three shorter (2.78 Å) and one longer (2.85 Å) Al–Sn bond lengths. Sn is bonded to three equivalent Mg and four equivalent Al atoms to form a mixture of distorted edge and corner-sharing SnMg3Al4 pentagonal bipyramids.