Materials Data on La6Mg23Si by Materials Project

Mg23La6Si 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 to eight Mg and four equivalent La atoms to form MgLa4Mg8 cuboctahedra that share corners with four equivalent MgLa4Mg8 cuboctahedra, edges with two equivalent SiLa6 octahedra, and faces with eight equivalent MgLa4Mg8 cuboctahedra. There are four shorter (2.99 Å) and four longer (3.19 Å) Mg–Mg bond lengths. All Mg–La bond lengths are 3.71 Å. In the second Mg site, Mg is bonded in a 12-coordinate geometry to nine Mg and three equivalent La atoms. There are three shorter (3.21 Å) and three longer (3.43 Å) Mg–Mg bond lengths. All Mg–La bond lengths are 3.51 Å. In the third Mg site, Mg is bonded in a body-centered cubic geometry to eight equivalent Mg atoms. All Mg–Mg bond lengths are 3.11 Å. In the fourth Mg site, Mg is bonded in a 10-coordinate geometry to seven Mg and three equivalent La atoms. All Mg–La bond lengths are 3.56 Å. La is bonded in a distorted single-bond geometry to twelve Mg and one Si atom. The La–Si bond length is 3.04 Å. Si is bonded to six equivalent La atoms to form SiLa6 octahedra that share edges with twelve equivalent MgLa4Mg8 cuboctahedra.