Materials Data on NaFe3P2(H4O7)2 by Materials Project
NaFe3P2(H4O7)2 crystallizes in the tetragonal P4_12_12 space group. The structure is three-dimensional. Na1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Na–O bond distances ranging from 2.45–2.80 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 and corners with three equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–48°. There are a spread of Fe–O bond distances ranging from 1.99–2.19 Å. In the second Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four equivalent FeO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 47–48°. There are two shorter (2.03 Å) and four longer (2.05 Å) Fe–O bond lengths. 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 42–52°. There is three shorter (1.55 Å) and one longer (1.56 Å) P–O bond length. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.64 Å) H–O bond length. 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 0.98 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. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to one Fe3+, one P5+, and one H1+ atom. In the second O2- site, O2- is bonded in a distorted water-like geometry to one Na1+, one Fe3+, and two H1+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Fe3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two Fe3+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Na1+, one Fe3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Fe3+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to two Fe3+ and one H1+ atom.