Materials Data on Ce2Mg by Materials Project

Abstract

MgCe2 is beta-derived structured and crystallizes in the trigonal R32 space group. The structure is three-dimensional. there are three inequivalent Mg sites. In the first Mg site, Mg is bonded to three equivalent Mg and nine Ce atoms to form distorted MgCe9Mg3 cuboctahedra that share corners with six equivalent CeCe6Mg6 cuboctahedra, corners with twelve MgCe9Mg3 cuboctahedra, edges with six equivalent MgCe9Mg3 cuboctahedra, edges with twelve CeCe8Mg4 cuboctahedra, faces with four MgCe9Mg3 cuboctahedra, and faces with sixteen CeCe8Mg4 cuboctahedra. All Mg–Mg bond lengths are 3.34 Å. There are a spread of Mg–Ce bond distances ranging from 3.34–3.41 Å. In the second Mg site, Mg is bonded to three equivalent Mg and nine Ce atoms to form distorted MgCe9Mg3 cuboctahedra that share corners with six equivalent CeCe6Mg6 cuboctahedra, corners with twelve MgCe9Mg3 cuboctahedra, edges with six equivalent MgCe9Mg3 cuboctahedra, edges with twelve CeCe8Mg4 cuboctahedra, faces with four MgCe9Mg3 cuboctahedra, and faces with sixteen CeCe8Mg4 cuboctahedra. There are a spread of Mg–Ce bond distances ranging from 3.34–3.41 Å. In the third Mg site, Mg is bonded to three equivalent Mg and nine Ce atoms to form distorted MgCe9Mg3 cuboctahedra that share corners with six equivalent CeCe6Mg6 cuboctahedra, corners with twelve MgCe9Mg3 cuboctahedra, edges with six equivalent MgCe9Mg3 cuboctahedra, edges with twelve CeCe8Mg4 cuboctahedra, faces with four equivalent MgCe9Mg3 cuboctahedra, and faces with sixteen CeCe8Mg4 cuboctahedra. All Mg–Mg bond lengths are 3.34 Å. There are a spread of Mg–Ce bond distances ranging from 3.34–3.41 Å. There are five inequivalent Ce sites. In the first Ce site, Ce is bonded to four Mg and eight Ce atoms to form distorted CeCe8Mg4 cuboctahedra that share corners with eighteen CeCe8Mg4 cuboctahedra, edges with eight MgCe9Mg3 cuboctahedra, edges with ten CeCe8Mg4 cuboctahedra, faces with eight MgCe9Mg3 cuboctahedra, and faces with twelve CeCe8Mg4 cuboctahedra. There are a spread of Ce–Ce bond distances ranging from 3.04–3.50 Å. In the second Ce site, Ce is bonded to four Mg and eight Ce atoms to form distorted CeCe8Mg4 cuboctahedra that share corners with eighteen CeCe8Mg4 cuboctahedra, edges with eight MgCe9Mg3 cuboctahedra, edges with ten CeCe8Mg4 cuboctahedra, faces with eight MgCe9Mg3 cuboctahedra, and faces with twelve CeCe8Mg4 cuboctahedra. There are a spread of Ce–Ce bond distances ranging from 3.04–3.50 Å. In the third Ce site, Ce is bonded to six Mg and six Ce atoms to form CeCe6Mg6 cuboctahedra that share corners with six equivalent CeCe6Mg6 cuboctahedra, corners with twelve MgCe9Mg3 cuboctahedra, edges with eighteen CeCe8Mg4 cuboctahedra, faces with eight MgCe9Mg3 cuboctahedra, and faces with twelve CeCe8Mg4 cuboctahedra. All Ce–Ce bond lengths are 3.46 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 eighteen CeCe8Mg4 cuboctahedra, edges with eight MgCe9Mg3 cuboctahedra, edges with ten CeCe6Mg6 cuboctahedra, faces with eight MgCe9Mg3 cuboctahedra, and faces with twelve CeCe8Mg4 cuboctahedra. In the fifth Ce site, Ce is bonded to four Mg and eight Ce atoms to form distorted CeCe8Mg4 cuboctahedra that share corners with eighteen CeCe8Mg4 cuboctahedra, edges with eight MgCe9Mg3 cuboctahedra, edges with ten CeCe6Mg6 cuboctahedra, faces with eight MgCe9Mg3 cuboctahedra, and faces with twelve CeCe8Mg4 cuboctahedra. There are one shorter (3.37 Å) and two longer (3.41 Å) Ce–Mg bond lengths. There are a spread of Ce–Ce bond distances ranging from 3.04–3.50 Å.