Materials Data on MgTi4O8 by Materials Project
MgTi4O8 crystallizes in the trigonal R-3m space group. The structure is three-dimensional. Mg2+ is bonded to six equivalent O2- atoms to form MgO6 octahedra that share corners with six equivalent TiO6 octahedra and edges with six equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 9°. All Mg–O bond lengths are 2.17 Å. There are two inequivalent Ti+3.50+ sites. In the first Ti+3.50+ site, Ti+3.50+ is bonded to six O2- atoms to form TiO6 octahedra that share edges with two equivalent MgO6 octahedra and edges with six TiO6 octahedra. There is two shorter (1.98 Å) and four longer (2.01 Å) Ti–O bond length. In the second Ti+3.50+ site, Ti+3.50+ is bonded to six equivalent O2- atoms to form TiO6 octahedra that share corners with six equivalent MgO6 octahedra and edges with six equivalent TiO6 octahedra. The corner-sharing octahedral tilt angles are 9°. All Ti–O bond lengths are 2.10 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Mg2+ and three Ti+3.50+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Ti+3.50+ atoms.