Materials Data on CaMg5 by Materials Project

Abstract

CaMg5 crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. Ca is bonded to twelve Mg atoms to form CaMg12 cuboctahedra that share corners with eighteen equivalent MgCa3Mg9 cuboctahedra, edges with six equivalent CaMg12 cuboctahedra, faces with two equivalent CaMg12 cuboctahedra, and faces with six equivalent MgCa3Mg9 cuboctahedra. There are six shorter (3.29 Å) and six longer (3.39 Å) Ca–Mg bond lengths. There are two inequivalent Mg sites. In the first Mg site, Mg is bonded in a 12-coordinate geometry to two equivalent Ca and eight Mg atoms. There are four shorter (3.18 Å) and four longer (3.26 Å) Mg–Mg bond lengths. In the second Mg site, Mg is bonded to three equivalent Ca and nine Mg atoms to form MgCa3Mg9 cuboctahedra that share corners with nine equivalent CaMg12 cuboctahedra, corners with nine equivalent MgCa3Mg9 cuboctahedra, edges with six equivalent MgCa3Mg9 cuboctahedra, faces with three equivalent CaMg12 cuboctahedra, and faces with five equivalent MgCa3Mg9 cuboctahedra. All Mg–Mg bond lengths are 3.29 Å.