Materials Data on CaMg5 by Materials Project

Abstract

CaMg5 is alpha Samarium-derived structured and crystallizes in the hexagonal P-6m2 space group. The structure is three-dimensional. Ca is bonded to six equivalent Ca and six equivalent Mg atoms to form CaCa6Mg6 cuboctahedra that share corners with six equivalent CaCa6Mg6 cuboctahedra, corners with twelve equivalent MgMg12 cuboctahedra, edges with six equivalent CaCa6Mg6 cuboctahedra, edges with twelve equivalent MgCa3Mg9 cuboctahedra, faces with six equivalent CaCa6Mg6 cuboctahedra, and faces with fourteen MgCa3Mg9 cuboctahedra. All Ca–Ca bond lengths are 3.30 Å. All Ca–Mg bond lengths are 3.47 Å. There are three inequivalent Mg sites. In the first Mg site, Mg is bonded to three equivalent Ca and nine Mg atoms to form MgCa3Mg9 cuboctahedra that share corners with eighteen MgCa3Mg9 cuboctahedra, edges with six equivalent CaCa6Mg6 cuboctahedra, edges with twelve MgCa3Mg9 cuboctahedra, faces with six equivalent CaCa6Mg6 cuboctahedra, and faces with fourteen MgCa3Mg9 cuboctahedra. There are three shorter (3.27 Å) and six longer (3.30 Å) Mg–Mg bond lengths. In the second Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with six equivalent CaCa6Mg6 cuboctahedra, corners with twelve equivalent MgMg12 cuboctahedra, edges with eighteen MgCa3Mg9 cuboctahedra, a faceface with one CaCa6Mg6 cuboctahedra, and faces with nineteen MgCa3Mg9 cuboctahedra. There are three shorter (3.29 Å) and six longer (3.30 Å) Mg–Mg bond lengths. In the third Mg site, Mg is bonded to twelve Mg atoms to form MgMg12 cuboctahedra that share corners with eighteen MgCa3Mg9 cuboctahedra, edges with eighteen MgMg12 cuboctahedra, and faces with twenty MgCa3Mg9 cuboctahedra. All Mg–Mg bond lengths are 3.30 Å.