DOE OSTI2020
BiMg2 crystallizes in the hexagonal P-62m space group. The structure is three-dimensional. there are two inequivalent Mg sites. In the first Mg site, Mg is bonded to eight Mg and four equivalent Bi atoms to form distorted MgMg8Bi4 cuboctahedra that share corners with eighteen equivalent MgMg8Bi4 cuboctahedra, edges with eight equivalent BiMg9Bi3 cuboctahedra, edges with ten MgMg8Bi4 cuboctahedra, faces with eight equivalent BiMg9Bi3 cuboctahedra, and faces with twelve MgMg8Bi4 cuboctahedra. There are a spread of Mg–Mg bond distances ranging from 3.31–3.36 Å. All Mg–Bi bond lengths are 3.33 Å. In the second Mg site, Mg is bonded to six equivalent Mg and six equivalent Bi atoms to form distorted MgMg6Bi6 cuboctahedra that share corners with eighteen equivalent BiMg9Bi3 cuboctahedra, edges with eighteen MgMg8Bi4 cuboctahedra, faces with six equivalent BiMg9Bi3 cuboctahedra, and faces with fourteen MgMg8Bi4 cuboctahedra. All Mg–Bi bond lengths are 3.34 Å. Bi is bonded to nine Mg and three equivalent Bi atoms to form distorted BiMg9Bi3 cuboctahedra that share corners with nine equivalent MgMg6Bi6 cuboctahedra, corners with nine equivalent BiMg9Bi3 cuboctahedra, edges with six equivalent BiMg9Bi3 cuboctahedra, edges with twelve equivalent MgMg8Bi4 cuboctahedra, faces with five equivalent BiMg9Bi3 cuboctahedra, and faces with fifteen MgMg8Bi4 cuboctahedra. All Bi–Bi bond lengths are 3.34 Å.