Materials Data on MgAl2(PO5)2 by Materials Project
MgAl2(PO5)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with four equivalent PO4 tetrahedra, and faces with two equivalent AlO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are a spread of Mg–O bond distances ranging from 2.03–2.09 Å. Al is bonded to six O atoms to form AlO6 octahedra that share a cornercorner with one MgO6 octahedra, corners with two equivalent AlO6 octahedra, corners with four equivalent PO4 tetrahedra, and a faceface with one MgO6 octahedra. The corner-sharing octahedra tilt angles range from 39–54°. There are a spread of Al–O bond distances ranging from 1.82–2.04 Å. P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and corners with four equivalent AlO6 octahedra. The corner-sharing octahedra tilt angles range from 30–49°. There are a spread of P–O bond distances ranging from 1.52–1.58 Å. There are five inequivalent O sites. In the first O site, O is bonded in a distorted T-shaped geometry to one Mg, one Al, and one P atom. In the second O site, O is bonded in a bent 150 degrees geometry to one Al and one P atom. In the third O site, O is bonded in a 3-coordinate geometry to one Mg, one Al, and one P atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to one Al and one P atom. In the fifth O site, O is bonded in a distorted T-shaped geometry to one Mg and two equivalent Al atoms.