Materials Data on BaAl3(PO7)2 by Materials Project

Abstract

BaAl3(PO7)2 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. Ba is bonded to twelve O atoms to form BaO12 cuboctahedra that share corners with six PO4 tetrahedra and faces with six AlO6 octahedra. There are a spread of Ba–O bond distances ranging from 2.85–3.01 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four AlO6 octahedra, corners with two PO4 tetrahedra, and faces with two equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 36–39°. There are a spread of Al–O bond distances ranging from 1.85–1.98 Å. In the second Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four equivalent AlO6 octahedra, corners with two PO4 tetrahedra, and faces with two equivalent BaO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 36–39°. There are a spread of Al–O bond distances ranging from 1.85–2.09 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 three equivalent BaO12 cuboctahedra and corners with three AlO6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There are a spread of P–O bond distances ranging from 1.53–1.56 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three equivalent BaO12 cuboctahedra and corners with three AlO6 octahedra. The corner-sharing octahedra tilt angles range from 52–55°. There is one shorter (1.54 Å) and three longer (1.55 Å) P–O bond length. There are ten inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Ba and two equivalent Al atoms. In the second O site, O is bonded in a single-bond geometry to one P atom. In the third O site, O is bonded in a 2-coordinate geometry to one Ba, one Al, and one P atom. In the fourth O site, O is bonded in a single-bond geometry to one P atom. In the fifth O site, O is bonded in a bent 150 degrees geometry to one Ba and two Al atoms. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Ba and two equivalent Al atoms. In the seventh O site, O is bonded in a 2-coordinate geometry to one Ba, one Al, and one P atom. In the eighth O site, O is bonded in a distorted bent 120 degrees geometry to one Ba, one Al, and one P atom. In the ninth O site, O is bonded in a distorted bent 150 degrees geometry to one Ba and two Al atoms. In the tenth O site, O is bonded in a 2-coordinate geometry to one Ba, one Al, and one P atom.