Materials Data on SrMg5 by Materials Project

Abstract

SrMg5 crystallizes in the trigonal R32 space group. The structure is three-dimensional. Sr is bonded to twelve Mg atoms to form SrMg12 cuboctahedra that share corners with six equivalent SrMg12 cuboctahedra, corners with twelve equivalent MgSr3Mg9 cuboctahedra, edges with six equivalent SrMg12 cuboctahedra, edges with twelve equivalent MgSr2Mg10 cuboctahedra, and faces with twenty MgSr2Mg10 cuboctahedra. There are six shorter (3.34 Å) and six longer (3.48 Å) Sr–Mg bond lengths. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded to two equivalent Sr and ten Mg atoms to form distorted MgSr2Mg10 cuboctahedra that share corners with eighteen equivalent MgSr2Mg10 cuboctahedra, edges with four equivalent SrMg12 cuboctahedra, edges with fourteen MgSr2Mg10 cuboctahedra, faces with four equivalent SrMg12 cuboctahedra, and faces with sixteen MgSr2Mg10 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.28–3.48 Å. In the second Mg site, Mg is bonded to three equivalent Sr and nine Mg atoms to form distorted MgSr3Mg9 cuboctahedra that share corners with six equivalent SrMg12 cuboctahedra, corners with twelve equivalent MgSr3Mg9 cuboctahedra, edges with eighteen MgSr2Mg10 cuboctahedra, faces with four equivalent SrMg12 cuboctahedra, and faces with sixteen MgSr2Mg10 cuboctahedra. All Mg–Mg bond lengths are 3.34 Å.