DOE OSTI2020
LaMg3 is Uranium Silicide structured and crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. there are three inequivalent Mg sites. In the first Mg site, Mg is bonded to eight Mg and four equivalent La atoms to form distorted MgLa4Mg8 cuboctahedra that share corners with twelve equivalent MgLa4Mg8 cuboctahedra, edges with eight equivalent LaMg12 cuboctahedra, edges with sixteen MgLa4Mg8 cuboctahedra, faces with four equivalent LaMg12 cuboctahedra, and faces with fourteen MgLa4Mg8 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.36–3.46 Å. There are two shorter (3.42 Å) and two longer (3.43 Å) Mg–La bond lengths. In the second Mg site, Mg is bonded to eight Mg and four equivalent La atoms to form distorted MgLa4Mg8 cuboctahedra that share corners with twelve equivalent MgLa4Mg8 cuboctahedra, edges with eight equivalent LaMg12 cuboctahedra, edges with sixteen MgLa4Mg8 cuboctahedra, faces with four equivalent LaMg12 cuboctahedra, and faces with fourteen MgLa4Mg8 cuboctahedra. All Mg–Mg bond lengths are 3.43 Å. All Mg–La bond lengths are 3.36 Å. In the third Mg site, Mg is bonded to eight Mg and four equivalent La atoms to form MgLa4Mg8 cuboctahedra that share corners with twelve equivalent MgLa4Mg8 cuboctahedra, edges with eight equivalent LaMg12 cuboctahedra, edges with sixteen MgLa4Mg8 cuboctahedra, faces with four equivalent LaMg12 cuboctahedra, and faces with fourteen MgLa4Mg8 cuboctahedra. There are two shorter (3.44 Å) and two longer (3.45 Å) Mg–La bond lengths. La is bonded to twelve Mg atoms to form LaMg12 cuboctahedra that share corners with twelve equivalent LaMg12 cuboctahedra, edges with twenty-four MgLa4Mg8 cuboctahedra, faces with six equivalent LaMg12 cuboctahedra, and faces with twelve MgLa4Mg8 cuboctahedra.