Materials Data on K2AlSn(PO4)3 by Materials Project
K2AlSn(PO4)3 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 6-coordinate geometry to twelve O2- atoms. There are a spread of K–O bond distances ranging from 2.88–3.35 Å. In the second K1+ site, K1+ is bonded in a 12-coordinate geometry to twelve O2- atoms. There are a spread of K–O bond distances ranging from 2.86–3.17 Å. Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with six equivalent PO4 tetrahedra. All Al–O bond lengths are 1.93 Å. Sn4+ is bonded to six O2- atoms to form SnO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are three shorter (2.04 Å) and three longer (2.05 Å) Sn–O bond lengths. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent AlO6 octahedra and corners with two equivalent SnO6 octahedra. The corner-sharing octahedra tilt angles range from 7–44°. There are a spread of P–O bond distances ranging from 1.53–1.57 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Al3+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Sn4+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to three K1+, one Sn4+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to three K1+, one Al3+, and one P5+ atom.