Materials Data on K3Ca(PO4)2 by Materials Project

Abstract

K3Ca(PO4)2 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a distorted q6 geometry to ten O atoms. There are a spread of K–O bond distances ranging from 3.02–3.21 Å. In the second K site, K is bonded in a 1-coordinate geometry to nine O atoms. There are a spread of K–O bond distances ranging from 2.63–3.12 Å. Ca is bonded to six O atoms to form CaO6 octahedra that share corners with six equivalent PO4 tetrahedra. There are four shorter (2.32 Å) and two longer (2.38 Å) Ca–O bond lengths. P is bonded to four O atoms to form PO4 tetrahedra that share corners with three equivalent CaO6 octahedra. The corner-sharing octahedra tilt angles range from 13–28°. There is two shorter (1.55 Å) and two longer (1.56 Å) P–O bond length. There are three inequivalent O sites. In the first O site, O is bonded in a 1-coordinate geometry to three K and one P atom. In the second O site, O is bonded in a 1-coordinate geometry to three K, one Ca, and one P atom. In the third O site, O is bonded in a 2-coordinate geometry to four K, one Ca, and one P atom.