Materials Data on Gd6Mg23C by Materials Project

Abstract

Mg23Gd6C crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded in a 1-coordinate geometry to ten Mg and three equivalent Gd atoms. There are a spread of Mg–Mg bond distances ranging from 2.97–3.43 Å. All Mg–Gd bond lengths are 3.74 Å. In the second Mg site, Mg is bonded to eight Mg and four equivalent Gd atoms to form distorted MgGd4Mg8 cuboctahedra that share corners with twelve MgGd4Mg8 cuboctahedra, edges with two equivalent CGd6 octahedra, and faces with sixteen MgGd4Mg8 cuboctahedra. All Mg–Mg bond lengths are 2.91 Å. All Mg–Gd bond lengths are 3.70 Å. In the third Mg site, Mg is bonded in a body-centered cubic geometry to eight equivalent Mg atoms. In the fourth Mg site, Mg is bonded to nine Mg and three equivalent Gd atoms to form distorted MgGd3Mg9 cuboctahedra that share corners with twelve MgGd4Mg8 cuboctahedra, faces with twelve MgGd4Mg8 cuboctahedra, and a faceface with one CGd6 octahedra. All Mg–Mg bond lengths are 3.27 Å. All Mg–Gd bond lengths are 3.41 Å. Gd is bonded in a single-bond geometry to twelve Mg and one C atom. The Gd–C bond length is 2.57 Å. C is bonded to six equivalent Gd atoms to form CGd6 octahedra that share edges with twelve equivalent MgGd4Mg8 cuboctahedra and faces with eight equivalent MgGd3Mg9 cuboctahedra.