Materials Data on KAl2P2O11 by Materials Project
KAl2P2O11 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K is bonded in a 7-coordinate geometry to seven O atoms. There are a spread of K–O bond distances ranging from 2.64–3.21 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded to six O atoms to form distorted AlO6 trigonal bipyramids that share corners with two equivalent AlO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 50–55°. There are a spread of Al–O bond distances ranging from 1.81–2.54 Å. In the second Al site, Al is bonded to six O atoms to form AlO6 octahedra that share corners with four PO4 tetrahedra, corners with two equivalent AlO6 trigonal bipyramids, and an edgeedge with one AlO6 octahedra. There are a spread of Al–O bond distances ranging from 1.83–2.09 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 two equivalent AlO6 octahedra and corners with two equivalent AlO6 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 46–59°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with two equivalent AlO6 octahedra and corners with two equivalent AlO6 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 40–48°. There is one shorter (1.54 Å) and three longer (1.55 Å) P–O bond length. There are eleven inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one K, one Al, and one P atom. In the second O site, O is bonded in a distorted trigonal planar geometry to three Al atoms. In the third O site, O is bonded in a distorted bent 150 degrees geometry to one K, one Al, and one P atom. In the fourth O site, O is bonded in a distorted bent 150 degrees geometry to one K, one Al, and one P atom. In the fifth O site, O is bonded in a distorted bent 120 degrees geometry to one K, one Al, and one P atom. In the sixth O site, O is bonded in a distorted single-bond geometry to two equivalent O atoms. There is one shorter (1.23 Å) and one longer (1.97 Å) O–O bond length. In the seventh O site, O is bonded in a 2-coordinate geometry to one K, one Al, and one P atom. In the eighth O site, O is bonded in a bent 150 degrees geometry to one Al and one P atom. In the ninth O site, O is bonded in a 2-coordinate geometry to one K, one Al, and one P atom. In the tenth O site, O is bonded in a distorted trigonal planar geometry to one K, one Al, and one P atom. In the eleventh O site, O is bonded in a 1-coordinate geometry to one Al and two equivalent O atoms.