Materials Data on Mg64Si31Bi by Materials Project
Mg64Si31Bi crystallizes in the cubic Pm-3m space group. The structure is three-dimensional. there are four inequivalent Mg sites. In the first Mg site, Mg is bonded to four Si atoms to form MgSi4 tetrahedra that share corners with sixteen MgSi3Bi tetrahedra and edges with six MgSi4 tetrahedra. All Mg–Si bond lengths are 2.76 Å. In the second Mg site, Mg is bonded to four Si atoms to form a mixture of edge and corner-sharing MgSi4 tetrahedra. There are three shorter (2.76 Å) and one longer (2.77 Å) Mg–Si bond lengths. In the third Mg site, Mg is bonded to four Si atoms to form a mixture of edge and corner-sharing MgSi4 tetrahedra. There are a spread of Mg–Si bond distances ranging from 2.75–2.77 Å. In the fourth Mg site, Mg is bonded to three equivalent Si and one Bi atom to form MgSi3Bi tetrahedra that share corners with sixteen MgSi4 tetrahedra and edges with six MgSi3Bi tetrahedra. All Mg–Si bond lengths are 2.71 Å. The Mg–Bi bond length is 2.94 Å. There are five inequivalent Si sites. In the first Si site, Si is bonded in a body-centered cubic geometry to eight equivalent Mg atoms. In the second Si site, Si is bonded in a body-centered cubic geometry to eight equivalent Mg atoms. In the third Si site, Si is bonded in a body-centered cubic geometry to eight equivalent Mg atoms. In the fourth Si site, Si is bonded in a body-centered cubic geometry to eight Mg atoms. In the fifth Si site, Si is bonded in a body-centered cubic geometry to eight Mg atoms. Bi is bonded in a body-centered cubic geometry to eight equivalent Mg atoms.