Materials Data on Mg2Ti5(PO4)6 by Materials Project
Mg2Ti5(PO4)6 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mg2+ is bonded to five O2- atoms to form MgO5 trigonal bipyramids that share a cornercorner with one TiO6 octahedra, corners with five PO4 tetrahedra, and edges with two TiO6 octahedra. The corner-sharing octahedral tilt angles are 63°. There are a spread of Mg–O bond distances ranging from 2.02–2.14 Å. There are three inequivalent Ti+2.80+ sites. In the first Ti+2.80+ site, Ti+2.80+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six PO4 tetrahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one MgO5 trigonal bipyramid. There are a spread of Ti–O bond distances ranging from 1.97–2.18 Å. In the second Ti+2.80+ site, Ti+2.80+ is bonded to six O2- atoms to form TiO6 octahedra that share a cornercorner with one TiO6 octahedra, corners with six PO4 tetrahedra, an edgeedge with one TiO6 octahedra, and an edgeedge with one MgO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 63°. There are a spread of Ti–O bond distances ranging from 1.97–2.19 Å. In the third Ti+2.80+ site, Ti+2.80+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with two equivalent TiO6 octahedra, corners with six PO4 tetrahedra, and corners with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 63°. There are a spread of Ti–O bond distances ranging from 2.05–2.23 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with five TiO6 octahedra and corners with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 33–60°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with six TiO6 octahedra and a cornercorner with one MgO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 20–56°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four TiO6 octahedra and corners with two equivalent MgO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 26–58°. There is two shorter (1.53 Å) and two longer (1.57 Å) P–O bond length. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Ti+2.80+, and one P5+ atom. In the second O2- site, O2- is bonded in a trigonal planar geometry to two Ti+2.80+ and one P5+ atom. In the third O2- site, O2- is bonded in a 3-coordinate geometry to one Mg2+, one Ti+2.80+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti+2.80+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti+2.80+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to one Mg2+, one Ti+2.80+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Ti+2.80+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ti+2.80+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to two equivalent Ti+2.80+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Ti+2.80+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ti+2.80+ and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted trigonal planar geometry to one Mg2+, one Ti+2.80+, and one P5+ atom.