Materials Data on Mg2Ti7O15 by Materials Project
Mg2Ti7O15 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with two equivalent TiO6 octahedra, and edges with six TiO6 octahedra. The corner-sharing octahedra tilt angles range from 30–46°. There are a spread of Mg–O bond distances ranging from 2.03–2.18 Å. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form distorted MgO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with two equivalent TiO6 octahedra, and edges with six TiO6 octahedra. The corner-sharing octahedra tilt angles range from 27–46°. There are a spread of Mg–O bond distances ranging from 2.01–2.18 Å. There are four inequivalent Ti+3.71+ sites. In the first Ti+3.71+ site, Ti+3.71+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share corners with three TiO6 octahedra, edges with two equivalent MgO6 octahedra, and edges with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 30–49°. There are a spread of Ti–O bond distances ranging from 1.91–2.14 Å. In the second Ti+3.71+ site, Ti+3.71+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with three TiO6 octahedra, edges with two equivalent MgO6 octahedra, and edges with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 27–52°. There are a spread of Ti–O bond distances ranging from 1.83–2.18 Å. In the third Ti+3.71+ site, Ti+3.71+ is bonded to six O2- atoms to form distorted TiO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with three TiO6 octahedra, edges with two MgO6 octahedra, and edges with three TiO6 octahedra. The corner-sharing octahedra tilt angles range from 30–50°. There are a spread of Ti–O bond distances ranging from 1.83–2.19 Å. In the fourth Ti+3.71+ site, Ti+3.71+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Ti–O bond distances ranging from 1.95–2.15 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted T-shaped geometry to three Ti+3.71+ atoms. In the second O2- site, O2- is bonded to one Mg2+ and three Ti+3.71+ atoms to form a mixture of distorted corner and edge-sharing OMgTi3 trigonal pyramids. In the third O2- site, O2- is bonded to one Mg2+ and three Ti+3.71+ atoms to form distorted OMgTi3 trigonal pyramids that share corners with four OMgTi3 trigonal pyramids and edges with four OTi4 trigonal pyramids. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+ and two Ti+3.71+ atoms. In the fifth O2- site, O2- is bonded to one Mg2+ and three Ti+3.71+ atoms to form a mixture of distorted corner and edge-sharing OMgTi3 trigonal pyramids. In the sixth O2- site, O2- is bonded to two Mg2+ and two equivalent Ti+3.71+ atoms to form a mixture of distorted corner and edge-sharing OMg2Ti2 trigonal pyramids. In the seventh O2- site, O2- is bonded to one Mg2+ and three Ti+3.71+ atoms to form distorted OMgTi3 trigonal pyramids that share corners with four OMgTi3 trigonal pyramids and edges with four OTi4 trigonal pyramids. In the eighth O2- site, O2- is bonded to four Ti+3.71+ atoms to form a mixture of distorted corner and edge-sharing OTi4 trigonal pyramids. In the ninth O2- site, O2- is bonded in a distorted T-shaped geometry to one Mg2+ and two equivalent Ti+3.71+ atoms.