Materials Data on Th6Mg23 by Materials Project
Mg23Th6 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 Th atoms. There are a spread of Mg–Mg bond distances ranging from 2.97–3.43 Å. All Mg–Th bond lengths are 3.71 Å. In the second Mg site, Mg is bonded to nine Mg and three equivalent Th atoms to form a mixture of distorted corner and face-sharing MgTh3Mg9 cuboctahedra. There are three shorter (2.92 Å) and three longer (3.24 Å) Mg–Mg bond lengths. All Mg–Th bond lengths are 3.45 Å. In the third Mg site, Mg is bonded to eight Mg and four equivalent Th atoms to form distorted MgTh4Mg8 cuboctahedra that share corners with twelve MgTh4Mg8 cuboctahedra and faces with sixteen MgTh3Mg9 cuboctahedra. All Mg–Th bond lengths are 3.70 Å. In the fourth Mg site, Mg is bonded in a body-centered cubic geometry to eight equivalent Mg atoms. Th is bonded in a 4-coordinate geometry to twelve Mg and four equivalent Th atoms. All Th–Th bond lengths are 3.72 Å.