Materials Data on CeMg2 by Materials Project

Abstract

CeMg2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded to nine Mg and three Ce atoms to form distorted MgCe3Mg9 cuboctahedra that share corners with eighteen MgCe3Mg9 cuboctahedra, edges with eight MgCe5Mg7 cuboctahedra, edges with ten CeCe4Mg8 cuboctahedra, faces with seven CeCe4Mg8 cuboctahedra, and faces with thirteen MgCe3Mg9 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.50 Å. There are one shorter (3.45 Å) and two longer (3.48 Å) Mg–Ce bond lengths. In the second Mg site, Mg is bonded to seven Mg and five Ce atoms to form MgCe5Mg7 cuboctahedra that share corners with eighteen MgCe3Mg9 cuboctahedra, edges with eight CeCe4Mg8 cuboctahedra, edges with ten MgCe3Mg9 cuboctahedra, faces with eight CeCe4Mg8 cuboctahedra, and faces with twelve MgCe3Mg9 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.28 Å. There are three shorter (3.38 Å) and two longer (3.42 Å) Mg–Ce bond lengths. In the third Mg site, Mg is bonded to eight Mg and four Ce atoms to form MgCe4Mg8 cuboctahedra that share corners with eighteen MgCe3Mg9 cuboctahedra, edges with six CeCe4Mg8 cuboctahedra, edges with twelve MgCe3Mg9 cuboctahedra, faces with nine CeCe4Mg8 cuboctahedra, and faces with eleven MgCe3Mg9 cuboctahedra. There are two shorter (3.18 Å) and two longer (3.24 Å) Mg–Mg bond lengths. There are a spread of Mg–Ce bond distances ranging from 3.37–3.48 Å. In the fourth Mg site, Mg is bonded to eight Mg and four Ce atoms to form distorted MgCe4Mg8 cuboctahedra that share corners with six equivalent MgCe4Mg8 cuboctahedra, corners with twelve CeCe4Mg8 cuboctahedra, edges with six CeCe4Mg8 cuboctahedra, edges with twelve MgCe3Mg9 cuboctahedra, faces with six CeCe4Mg8 cuboctahedra, and faces with fourteen MgCe3Mg9 cuboctahedra. Both Mg–Mg bond lengths are 3.18 Å. There are two shorter (3.43 Å) and two longer (3.46 Å) Mg–Ce bond lengths. There are two inequivalent Ce sites. In the first Ce site, Ce is bonded to eight Mg and four Ce atoms to form CeCe4Mg8 cuboctahedra that share corners with six equivalent MgCe4Mg8 cuboctahedra, corners with twelve CeCe4Mg8 cuboctahedra, edges with three equivalent CeCe4Mg8 cuboctahedra, edges with fifteen MgCe3Mg9 cuboctahedra, faces with five CeCe4Mg8 cuboctahedra, and faces with fifteen MgCe3Mg9 cuboctahedra. There are two shorter (2.82 Å) and two longer (3.18 Å) Ce–Ce bond lengths. In the second Ce site, Ce is bonded to eight Mg and four Ce atoms to form CeCe4Mg8 cuboctahedra that share corners with six equivalent MgCe4Mg8 cuboctahedra, corners with twelve CeCe4Mg8 cuboctahedra, edges with three equivalent CeCe4Mg8 cuboctahedra, edges with fifteen MgCe3Mg9 cuboctahedra, faces with five CeCe4Mg8 cuboctahedra, and faces with fifteen MgCe3Mg9 cuboctahedra. Both Ce–Ce bond lengths are 3.18 Å.