Materials Data on Mg2Al4Fe(PO6)4 by Materials Project
Mg2FeAl4(PO6)4 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with four PO4 tetrahedra, an edgeedge with one FeO6 octahedra, and a faceface with one AlO6 octahedra. The corner-sharing octahedra tilt angles range from 46–54°. There are a spread of Mg–O bond distances ranging from 2.08–2.22 Å. Fe is bonded to six O atoms to form FeO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with four equivalent PO4 tetrahedra, and edges with two equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 46°. There are a spread of Fe–O bond distances ranging from 2.01–2.07 Å. There are three inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with two equivalent AlO6 octahedra, and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–46°. There is four shorter (1.88 Å) and two longer (1.90 Å) Al–O bond length. In the second Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two AlO6 octahedra, and corners with three PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 36–54°. There are a spread of Al–O bond distances ranging from 1.84–1.95 Å. In the third Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with two equivalent AlO6 octahedra, corners with four equivalent PO4 tetrahedra, and faces with two equivalent MgO6 octahedra. The corner-sharing octahedral tilt angles are 44°. There are a spread of Al–O bond distances ranging from 1.89–1.98 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra and corners with four AlO6 octahedra. The corner-sharing octahedra tilt angles range from 37–52°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent FeO6 octahedra, and corners with two AlO6 octahedra. The corner-sharing octahedra tilt angles range from 51–57°. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. There are twelve inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two Al atoms. 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 bent 150 degrees geometry to one Al and one P atom. In the fourth O site, O is bonded in a distorted trigonal planar geometry to one Mg, one Fe, and one P atom. In the fifth O site, O is bonded in a bent 120 degrees geometry to one Al and one P atom. In the sixth O site, O is bonded in a bent 120 degrees geometry to one Al and one P atom. In the seventh O site, O is bonded in a 3-coordinate geometry to one Mg, one Al, and one P atom. In the eighth O site, O is bonded in a distorted bent 120 degrees geometry to one Mg and one Al atom. In the ninth O site, O is bonded in a distorted T-shaped geometry to one Mg and two Al atoms. In the tenth O site, O is bonded in a distorted trigonal planar geometry to one Mg, one Fe, and one P atom. In the eleventh O site, O is bonded in a 3-coordinate geometry to one Mg, one Al, and one P atom. In the twelfth O site, O is bonded in a distorted bent 120 degrees geometry to one Fe and one Al atom.