Materials Data on Li2MgSi by Materials Project

Abstract

Li2MgSi crystallizes in the cubic P-43m space group. The structure is three-dimensional. there are three inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four equivalent Li1+ and four equivalent Si4- atoms to form distorted LiLi4Si4 tetrahedra that share corners with sixteen MgSi4 tetrahedra and edges with six equivalent LiSi4 tetrahedra. All Li–Li bond lengths are 2.51 Å. All Li–Si bond lengths are 2.73 Å. In the second Li1+ site, Li1+ is bonded to four equivalent Si4- atoms to form LiSi4 tetrahedra that share corners with eight equivalent LiSi4 tetrahedra, corners with eight MgSi4 tetrahedra, edges with two equivalent LiLi4Si4 tetrahedra, and edges with four equivalent MgSi4 tetrahedra. All Li–Si bond lengths are 2.75 Å. In the third Li1+ site, Li1+ is bonded in a 4-coordinate geometry to one Li1+ and three equivalent Si4- atoms. All Li–Si bond lengths are 3.03 Å. There are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to four equivalent Si4- atoms to form MgSi4 tetrahedra that share corners with sixteen LiLi4Si4 tetrahedra and edges with six equivalent MgSi4 tetrahedra. All Mg–Si bond lengths are 2.78 Å. In the second Mg2+ site, Mg2+ is bonded to four equivalent Si4- atoms to form MgSi4 tetrahedra that share corners with eight LiLi4Si4 tetrahedra, corners with eight equivalent MgSi4 tetrahedra, edges with two equivalent MgSi4 tetrahedra, and edges with four equivalent LiSi4 tetrahedra. All Mg–Si bond lengths are 2.77 Å. Si4- is bonded in a distorted body-centered cubic geometry to seven Li1+ and four Mg2+ atoms.