DOE OSTI2020
Mg3Yb is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm 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 Yb atoms to form MgYb4Mg8 cuboctahedra that share corners with four equivalent MgYb4Mg8 cuboctahedra, corners with eight equivalent YbMg12 cuboctahedra, edges with eight equivalent MgYb4Mg8 cuboctahedra, faces with four equivalent MgYb4Mg8 cuboctahedra, and faces with six equivalent YbMg12 cuboctahedra. All Mg–Mg bond lengths are 3.24 Å. All Mg–Yb bond lengths are 3.58 Å. In the second Mg site, Mg is bonded in a distorted body-centered cubic geometry to four equivalent Mg and four equivalent Yb atoms. All Mg–Yb bond lengths are 3.24 Å. Yb is bonded to twelve Mg atoms to form distorted YbMg12 cuboctahedra that share corners with four equivalent YbMg12 cuboctahedra, corners with eight equivalent MgYb4Mg8 cuboctahedra, edges with eight equivalent YbMg12 cuboctahedra, faces with four equivalent YbMg12 cuboctahedra, and faces with six equivalent MgYb4Mg8 cuboctahedra.