Materials Data on K2Fe2(PO4)3 by Materials Project
K2Fe2(PO4)3 crystallizes in the cubic P2_13 space group. The structure is three-dimensional. there are two inequivalent K sites. In the first 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 2.88–3.17 Å. In the second K site, K is bonded in a 12-coordinate geometry to twelve O atoms. There are a spread of K–O bond distances ranging from 2.91–3.28 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are three shorter (2.01 Å) and three longer (2.02 Å) Fe–O bond lengths. In the second Fe site, Fe is bonded to six O atoms to form FeO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are three shorter (2.02 Å) and three longer (2.03 Å) Fe–O bond lengths. P is bonded to four O atoms to form PO4 tetrahedra that share corners with four FeO6 octahedra. The corner-sharing octahedra tilt angles range from 15–49°. 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 three K, one Fe, and one P atom. In the second O site, O is bonded in a distorted bent 150 degrees geometry to one K, one Fe, and one P atom. In the third O site, O is bonded in a 2-coordinate geometry to two K, one Fe, and one P atom. In the fourth O site, O is bonded in a 3-coordinate geometry to one K, one Fe, and one P atom.