Materials Data on KAlPO5 by Materials Project

KAlPO5 crystallizes in the orthorhombic Pnna space group. The structure is three-dimensional. K is bonded in a 5-coordinate geometry to five O atoms. There are a spread of K–O bond distances ranging from 2.59–2.87 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 two equivalent AlO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There is four shorter (1.87 Å) and two longer (2.00 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 AlO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedral tilt angles are 47°. There are a spread of Al–O bond distances ranging from 1.86–2.00 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 four AlO6 octahedra. The corner-sharing octahedra tilt angles range from 46–47°. There is two shorter (1.54 Å) and two longer (1.56 Å) P–O bond length. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with four AlO6 octahedra. The corner-sharing octahedra tilt angles range from 43–49°. All P–O bond lengths are 1.55 Å. There are five inequivalent O sites. In the first O site, O is bonded in a 2-coordinate geometry to one K, one Al, and one P atom. In the second O site, O is bonded in a 2-coordinate geometry to one K, one Al, and one P atom. In the third O site, O is bonded in a 3-coordinate geometry to one K, one Al, and one P atom. In the fourth O site, O is bonded in a 2-coordinate geometry to one K, one Al, and one P atom. In the fifth O site, O is bonded in a 3-coordinate geometry to one K and two Al atoms.