Materials Data on Li2MgSiO4 by Materials Project

Abstract

Li2MgSiO4 is beta beryllia-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent LiO4 tetrahedra, corners with four equivalent MgO4 tetrahedra, corners with four equivalent SiO4 tetrahedra, and an edgeedge with one LiO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.96–2.04 Å. In the second Li1+ site, Li1+ is bonded to four O2- atoms to form LiO4 tetrahedra that share corners with two equivalent LiO4 tetrahedra, corners with two equivalent MgO4 tetrahedra, corners with four equivalent SiO4 tetrahedra, an edgeedge with one LiO4 tetrahedra, and an edgeedge with one MgO4 tetrahedra. There are a spread of Li–O bond distances ranging from 1.96–2.10 Å. Mg2+ is bonded to four O2- atoms to form MgO4 tetrahedra that share corners with four equivalent SiO4 tetrahedra, corners with six LiO4 tetrahedra, and an edgeedge with one LiO4 tetrahedra. There are a spread of Mg–O bond distances ranging from 1.96–2.01 Å. Si4+ is bonded to four O2- atoms to form SiO4 tetrahedra that share corners with four equivalent MgO4 tetrahedra and corners with eight LiO4 tetrahedra. There is two shorter (1.65 Å) and two longer (1.66 Å) Si–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to two Li1+, one Mg2+, and one Si4+ atom to form a mixture of edge and corner-sharing OLi2MgSi tetrahedra. In the second O2- site, O2- is bonded to two Li1+, one Mg2+, and one Si4+ atom to form corner-sharing OLi2MgSi tetrahedra. In the third O2- site, O2- is bonded to two Li1+, one Mg2+, and one Si4+ atom to form a mixture of edge and corner-sharing OLi2MgSi tetrahedra. In the fourth O2- site, O2- is bonded to two Li1+, one Mg2+, and one Si4+ atom to form a mixture of distorted edge and corner-sharing OLi2MgSi trigonal pyramids.