Materials Data on Ce2Mg by Materials Project

Abstract

MgCe2 is beta-derived structured and crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Mg is bonded to two equivalent Mg and ten Ce atoms to form MgCe10Mg2 cuboctahedra that share corners with six equivalent MgCe10Mg2 cuboctahedra, corners with twelve CeCe6Mg6 cuboctahedra, edges with eight equivalent MgCe10Mg2 cuboctahedra, edges with ten CeCe6Mg6 cuboctahedra, faces with six equivalent MgCe10Mg2 cuboctahedra, and faces with fourteen CeCe6Mg6 cuboctahedra. Both Mg–Mg bond lengths are 3.24 Å. There are a spread of Mg–Ce bond distances ranging from 3.34–3.55 Å. There are two inequivalent Ce sites. In the first Ce site, Ce is bonded to six equivalent Mg and six Ce atoms to form distorted CeCe6Mg6 cuboctahedra that share corners with six equivalent MgCe10Mg2 cuboctahedra, corners with twelve CeCe6Mg6 cuboctahedra, edges with seven equivalent MgCe10Mg2 cuboctahedra, edges with eleven equivalent CeCe8Mg4 cuboctahedra, faces with six equivalent MgCe10Mg2 cuboctahedra, and faces with fourteen CeCe6Mg6 cuboctahedra. There are a spread of Ce–Ce bond distances ranging from 3.22–3.66 Å. In the second Ce site, Ce is bonded to four equivalent Mg and eight Ce atoms to form CeCe8Mg4 cuboctahedra that share corners with six equivalent MgCe10Mg2 cuboctahedra, corners with twelve CeCe8Mg4 cuboctahedra, edges with three equivalent MgCe10Mg2 cuboctahedra, edges with fifteen CeCe6Mg6 cuboctahedra, faces with eight equivalent MgCe10Mg2 cuboctahedra, and faces with twelve CeCe6Mg6 cuboctahedra. There are two shorter (3.24 Å) and four longer (3.40 Å) Ce–Ce bond lengths.