Materials Data on KFe2P2H5O11 by Materials Project
KFe2P2H3O10H2O crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional and consists of four water molecules and one KFe2P2H3O10 framework. In the KFe2P2H3O10 framework, K1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of K–O bond distances ranging from 2.84–3.04 Å. There are two inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one FeO6 octahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Fe–O bond distances ranging from 1.97–2.21 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 55–58°. There are a spread of Fe–O bond distances ranging from 1.95–2.22 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 four FeO6 octahedra. The corner-sharing octahedra tilt angles range from 33–58°. There are a spread of P–O bond distances ranging from 1.54–1.56 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four FeO6 octahedra. The corner-sharing octahedra tilt angles range from 34–50°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Fe3+, and one P5+ atom. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to 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 distorted single-bond geometry to three Fe3+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+, one Fe3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Fe3+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to one Fe3+ and two H1+ atoms. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Fe3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one Fe3+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+, one Fe3+, and one P5+ atom.