Materials Data on Li2MgSi5O12 by Materials Project
Li2MgSi5O12 is Esseneite-like structured and crystallizes in the tetragonal I4_1/acd space group. The structure is three-dimensional. Li1+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are a spread of Li–O bond distances ranging from 2.19–2.40 Å. Mg2+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are four shorter (2.17 Å) and four longer (2.36 Å) Mg–O bond lengths. There are three inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to six O2- atoms to form corner-sharing SiO6 octahedra. There are a spread of Si–O bond distances ranging from 1.78–1.81 Å. In the second Si4+ site, Si4+ is bonded to four equivalent O2- atoms to form corner-sharing SiO4 tetrahedra. The corner-sharing octahedral tilt angles are 46°. All Si–O bond lengths are 1.65 Å. In the third Si4+ site, Si4+ is bonded to four O2- atoms to form corner-sharing SiO4 tetrahedra. The corner-sharing octahedra tilt angles range from 44–46°. There is two shorter (1.64 Å) and two longer (1.66 Å) Si–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one Mg2+, and two Si4+ atoms. In the second O2- site, O2- is bonded in a 4-coordinate geometry to one Li1+, one Mg2+, and two Si4+ atoms. In the third O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Li1+ and two Si4+ atoms.