Materials Data on KFeCu(PO4)2 by Materials Project

Abstract

KCuFe(PO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.81–3.20 Å. Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with six PO4 tetrahedra and corners with two equivalent CuO5 trigonal bipyramids. There are a spread of Fe–O bond distances ranging from 1.97–2.21 Å. Cu2+ is bonded to five O2- atoms to form CuO5 trigonal bipyramids that share corners with two equivalent FeO6 octahedra, corners with three PO4 tetrahedra, an edgeedge with one PO4 tetrahedra, and an edgeedge with one CuO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 51–61°. There are a spread of Cu–O bond distances ranging from 1.94–2.23 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent FeO6 octahedra, a cornercorner with one CuO5 trigonal bipyramid, and an edgeedge with one CuO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 38–43°. There are a spread of P–O bond distances ranging from 1.53–1.58 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three equivalent FeO6 octahedra and corners with two equivalent CuO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 38–41°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Fe3+, and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Fe3+, and one P5+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Fe3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+, one Fe3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, two equivalent Cu2+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+, one Cu2+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one Fe3+, one Cu2+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Fe3+, one Cu2+, and one P5+ atom.