DOE OSTI2020
Mg3Tl is beta Cu3Ti-like structured and crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to eight equivalent Mg and four equivalent Tl atoms to form MgMg8Tl4 cuboctahedra that share corners with four equivalent TlMg12 cuboctahedra, corners with fourteen MgMg8Tl4 cuboctahedra, edges with six equivalent TlMg12 cuboctahedra, edges with twelve equivalent MgMg8Tl4 cuboctahedra, faces with four equivalent TlMg12 cuboctahedra, and faces with sixteen MgMg8Tl4 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.18–3.24 Å. There are two shorter (3.20 Å) and two longer (3.23 Å) Mg–Tl bond lengths. In the second Mg site, Mg is bonded to eight Mg and four equivalent Tl atoms to form MgMg8Tl4 cuboctahedra that share corners with four equivalent TlMg12 cuboctahedra, corners with fourteen MgMg8Tl4 cuboctahedra, edges with six equivalent TlMg12 cuboctahedra, edges with twelve MgMg8Tl4 cuboctahedra, faces with four equivalent TlMg12 cuboctahedra, and faces with sixteen MgMg8Tl4 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.17–3.24 Å. There are two shorter (3.21 Å) and two longer (3.23 Å) Mg–Tl bond lengths. Tl is bonded to twelve Mg atoms to form TlMg12 cuboctahedra that share corners with six equivalent TlMg12 cuboctahedra, corners with twelve MgMg8Tl4 cuboctahedra, edges with eighteen MgMg8Tl4 cuboctahedra, faces with eight equivalent TlMg12 cuboctahedra, and faces with twelve MgMg8Tl4 cuboctahedra.