DOI: 10.17188/1754797
title: Materials Data on Fe6P4H23O21 by Materials Project

description: Fe6P4(H3O7)3(H2)7 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional and consists of sixteen hydrogen molecules, eight molecular hydrogen molecules, and one Fe6P4(H3O7)3 framework. In the Fe6P4(H3O7)3 framework, there are four inequivalent Fe+2.50+ sites. In the first Fe+2.50+ site, Fe+2.50+ is bonded to four O2- atoms to form distorted FeO4 tetrahedra that share corners with two FeO6 octahedra, a cornercorner with one FeO4 tetrahedra, a cornercorner with one PO4 tetrahedra, and a cornercorner with one PO4 trigonal pyramid. The corner-sharing octahedra tilt angles range from 54–63°. There are a spread of Fe–O bond distances ranging from 1.97–2.09 Å. In the second Fe+2.50+ site, Fe+2.50+ is bonded to six O2- atoms to form distorted FeO6 octahedra that share a cornercorner with one FeO4 tetrahedra, corners with two equivalent PO4 tetrahedra, corners with two equivalent PO4 trigonal pyramids, and a faceface with one FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.00–2.29 Å. In the third Fe+2.50+ site, Fe+2.50+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with two equivalent FeO4 tetrahedra, corners with four equivalent PO4 tetrahedra, and faces with two equivalent FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.02–2.11 Å. In the fourth Fe+2.50+ site, Fe+2.50+ is bonded in a square co-planar geometry to four O2- atoms. There are two shorter (1.98 Å) and two longer (2.14 Å) Fe–O bond lengths. There are two inequivalent P1+ sites. In the first P1+ site, P1+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four FeO6 octahedra and a cornercorner with one FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 28–57°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the second P1+ site, P1+ is bonded to four O2- atoms to form PO4 trigonal pyramids that share corners with two equivalent FeO6 octahedra and a cornercorner with one FeO4 tetrahedra. The corner-sharing octahedra tilt angles range from 32–61°. There are a spread of P–O bond distances ranging from 1.49–1.91 Å. There are five 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 0.98 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 0.97 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are eleven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two Fe+2.50+ and one H1+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe+2.50+ and one P1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to three Fe+2.50+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe+2.50+ and one P1+ atom. In the fifth O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one P1+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe+2.50+ and one P1+ atom. In the seventh O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Fe+2.50+ and one H1+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Fe+2.50+ and one P1+ atom. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to one Fe+2.50+ and one P1+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Fe+2.50+ and one P1+ atom. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe+2.50+ and one P1+ atom.