Materials Data on K7Be12(PO4)12 by Materials Project
K7Be12(PO4)12 crystallizes in the cubic I23 space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded to four equivalent O atoms to form distorted KO4 tetrahedra that share corners with four equivalent BeO4 tetrahedra and corners with four equivalent PO4 tetrahedra. All K–O bond lengths are 2.68 Å. In the second K site, K is bonded in a 9-coordinate geometry to nine O atoms. There are a spread of K–O bond distances ranging from 3.01–3.29 Å. Be is bonded to four O atoms to form BeO4 tetrahedra that share a cornercorner with one KO4 tetrahedra and corners with four equivalent PO4 tetrahedra. There are a spread of Be–O bond distances ranging from 1.62–1.65 Å. P is bonded to four O atoms to form PO4 tetrahedra that share a cornercorner with one KO4 tetrahedra and corners with four equivalent BeO4 tetrahedra. There is two shorter (1.54 Å) and two longer (1.55 Å) P–O bond length. There are four inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one K, one Be, and one P atom. In the second O site, O is bonded in a 3-coordinate geometry to one K, one Be, and one P atom. In the third O site, O is bonded in a distorted bent 120 degrees geometry to one K, one Be, and one P atom. In the fourth O site, O is bonded in a distorted bent 120 degrees geometry to one K, one Be, and one P atom.