Materials Data on Ce2Mg by Materials Project

Abstract

MgCe2 is beta-derived structured and crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to four Mg and eight Ce atoms to form MgCe8Mg4 cuboctahedra that share corners with six equivalent CeCe8Mg4 cuboctahedra, corners with twelve MgCe8Mg4 cuboctahedra, edges with three equivalent MgCe8Mg4 cuboctahedra, edges with fifteen CeCe6Mg6 cuboctahedra, faces with six MgCe8Mg4 cuboctahedra, and faces with fourteen CeCe10Mg2 cuboctahedra. There are two shorter (3.11 Å) and two longer (3.24 Å) Mg–Mg bond lengths. There are a spread of Mg–Ce bond distances ranging from 3.30–3.49 Å. In the second Mg site, Mg is bonded to four Mg and eight Ce atoms to form MgCe8Mg4 cuboctahedra that share corners with six equivalent CeCe8Mg4 cuboctahedra, corners with twelve MgCe8Mg4 cuboctahedra, edges with three equivalent MgCe8Mg4 cuboctahedra, edges with fifteen CeCe10Mg2 cuboctahedra, faces with six MgCe8Mg4 cuboctahedra, and faces with fourteen CeCe10Mg2 cuboctahedra. Both Mg–Mg bond lengths are 3.24 Å. There are a spread of Mg–Ce bond distances ranging from 3.40–3.48 Å. There are four inequivalent Ce sites. In the first Ce site, Ce is bonded to two equivalent Mg and ten Ce atoms to form CeCe10Mg2 cuboctahedra that share corners with eighteen CeCe10Mg2 cuboctahedra, edges with eight equivalent MgCe8Mg4 cuboctahedra, edges with ten CeCe8Mg4 cuboctahedra, faces with eight MgCe8Mg4 cuboctahedra, and faces with twelve CeCe10Mg2 cuboctahedra. There are a spread of Ce–Ce bond distances ranging from 3.23–3.49 Å. In the second Ce site, Ce is bonded to four equivalent Mg and eight Ce atoms to form distorted CeCe8Mg4 cuboctahedra that share corners with eighteen CeCe10Mg2 cuboctahedra, edges with six CeCe10Mg2 cuboctahedra, edges with twelve MgCe8Mg4 cuboctahedra, faces with six MgCe8Mg4 cuboctahedra, and faces with fourteen CeCe10Mg2 cuboctahedra. There are a spread of Ce–Ce bond distances ranging from 3.17–3.62 Å. In the third Ce site, Ce is bonded to six Mg and six Ce atoms to form CeCe6Mg6 cuboctahedra that share corners with eighteen CeCe10Mg2 cuboctahedra, edges with four equivalent MgCe8Mg4 cuboctahedra, edges with fourteen CeCe10Mg2 cuboctahedra, faces with ten MgCe8Mg4 cuboctahedra, and faces with ten CeCe10Mg2 cuboctahedra. Both Ce–Ce bond lengths are 3.24 Å. In the fourth Ce site, Ce is bonded to four Mg and eight Ce atoms to form distorted CeCe8Mg4 cuboctahedra that share corners with six equivalent CeCe8Mg4 cuboctahedra, corners with twelve MgCe8Mg4 cuboctahedra, edges with six MgCe8Mg4 cuboctahedra, edges with twelve CeCe10Mg2 cuboctahedra, faces with four MgCe8Mg4 cuboctahedra, and faces with sixteen CeCe10Mg2 cuboctahedra. Both Ce–Ce bond lengths are 3.24 Å.