Materials Data on Ca5Mg by Materials Project

Abstract

Ca5Mg crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. there are two inequivalent Ca sites. In the first Ca site, Ca is bonded to ten Ca and two equivalent Mg atoms to form distorted CaCa10Mg2 cuboctahedra that share corners with eighteen equivalent CaCa10Mg2 cuboctahedra, edges with four equivalent MgCa12 cuboctahedra, edges with fourteen CaCa10Mg2 cuboctahedra, faces with four equivalent MgCa12 cuboctahedra, and faces with sixteen CaCa10Mg2 cuboctahedra. There are a spread of Ca–Ca bond distances ranging from 3.66–3.83 Å. Both Ca–Mg bond lengths are 3.74 Å. In the second Ca site, Ca is bonded to nine Ca and three equivalent Mg atoms to form CaCa9Mg3 cuboctahedra that share corners with nine equivalent CaCa9Mg3 cuboctahedra, corners with nine equivalent MgCa12 cuboctahedra, edges with eighteen CaCa10Mg2 cuboctahedra, faces with three equivalent MgCa12 cuboctahedra, and faces with seventeen CaCa10Mg2 cuboctahedra. All Ca–Ca bond lengths are 3.77 Å. All Ca–Mg bond lengths are 3.77 Å. Mg is bonded to twelve Ca atoms to form MgCa12 cuboctahedra that share corners with eighteen equivalent CaCa9Mg3 cuboctahedra, edges with six equivalent MgCa12 cuboctahedra, edges with twelve equivalent CaCa10Mg2 cuboctahedra, faces with two equivalent MgCa12 cuboctahedra, and faces with eighteen CaCa10Mg2 cuboctahedra.