DOI: 10.17188/1280032
title: Materials Data on KFeCo3(PO4)3 by Materials Project

description: KFeCo3(PO4)3 crystallizes in the orthorhombic Pnnm space group. The structure is three-dimensional. K1+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.80–3.18 Å. Fe2+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four PO4 tetrahedra, edges with two equivalent CoO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Fe–O bond distances ranging from 2.04–2.30 Å. There are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded to five O2- atoms to form CoO5 trigonal bipyramids that share corners with two equivalent CoO6 octahedra, corners with five PO4 tetrahedra, and an edgeedge with one CoO5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 63°. There are a spread of Co–O bond distances ranging from 1.99–2.25 Å. In the second Co2+ site, Co2+ is bonded to six O2- atoms to form distorted CoO6 octahedra that share a cornercorner with one FeO6 octahedra, corners with four PO4 tetrahedra, a cornercorner with one CoO5 trigonal bipyramid, an edgeedge with one FeO6 octahedra, edges with two equivalent CoO6 octahedra, and an edgeedge with one PO4 tetrahedra. The corner-sharing octahedral tilt angles are 68°. There are a spread of Co–O bond distances ranging from 2.06–2.51 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with two equivalent CoO6 octahedra, corners with two equivalent CoO5 trigonal bipyramids, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 11–59°. There are a spread of P–O bond distances ranging from 1.52–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra, corners with two equivalent CoO6 octahedra, a cornercorner with one CoO5 trigonal bipyramid, and edges with two equivalent CoO6 octahedra. The corner-sharing octahedra tilt angles range from 45–51°. There are a spread of P–O bond distances ranging from 1.54–1.59 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one FeO6 octahedra, corners with four equivalent CoO6 octahedra, and corners with two equivalent CoO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 50–60°. There are a spread of P–O bond distances ranging from 1.53–1.61 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Fe2+, one Co2+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Co2+, and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one K1+, one Fe2+, one Co2+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+, one Fe2+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Co2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted tetrahedral geometry to three Co2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Co2+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Co2+ and one P5+ atom. In the ninth O2- site, O2- is bonded in a rectangular see-saw-like geometry to one Fe2+, two equivalent Co2+, and one P5+ atom.