Materials Data on Mg2Sn by Materials Project

Abstract

Mg2Sn crystallizes in the trigonal P-3m1 space group. The structure is two-dimensional and consists of one Mg2Sn sheet oriented in the (0, 0, 1) direction. there are three inequivalent Mg sites. In the first Mg site, Mg is bonded to twelve Mg atoms to form a mixture of edge, face, and corner-sharing MgMg12 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.21–3.26 Å. In the second Mg site, Mg is bonded to nine Mg and three equivalent Sn atoms to form distorted MgMg9Sn3 cuboctahedra that share corners with twelve MgMg9Sn3 cuboctahedra, edges with twelve MgMg12 cuboctahedra, and faces with thirteen MgMg12 cuboctahedra. All Mg–Mg bond lengths are 3.26 Å. All Mg–Sn bond lengths are 3.21 Å. In the third Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with twelve MgMg9Sn3 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with nineteen MgMg12 cuboctahedra. There are three shorter (3.21 Å) and six longer (3.26 Å) Mg–Mg bond lengths. Sn is bonded in a 12-coordinate geometry to three equivalent Mg atoms.