DOI: 10.17188/1306536
title: Materials Data on Na7(FeO4)2 by Materials Project

description: Na7(FeO4)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are fourteen inequivalent Na sites. In the first Na site, Na is bonded to five O atoms to form distorted NaO5 trigonal bipyramids that share corners with three FeO4 tetrahedra, edges with two NaO6 pentagonal pyramids, and an edgeedge with one FeO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.26–2.55 Å. In the second Na site, Na is bonded to six O atoms to form distorted NaO6 pentagonal pyramids that share corners with two equivalent NaO6 pentagonal pyramids, corners with two FeO4 tetrahedra, edges with two FeO4 tetrahedra, and edges with two NaO5 trigonal bipyramids. There are a spread of Na–O bond distances ranging from 2.28–2.65 Å. In the third Na site, Na is bonded to five O atoms to form distorted NaO5 trigonal bipyramids that share corners with three FeO4 tetrahedra, edges with two NaO6 pentagonal pyramids, and an edgeedge with one FeO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.30–2.55 Å. In the fourth Na site, Na is bonded in a distorted pentagonal planar geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.44–2.59 Å. In the fifth Na site, Na is bonded to six O atoms to form distorted NaO6 pentagonal pyramids that share corners with two equivalent NaO6 pentagonal pyramids, corners with two FeO4 tetrahedra, edges with two FeO4 tetrahedra, and edges with two NaO5 trigonal bipyramids. There are a spread of Na–O bond distances ranging from 2.27–2.70 Å. In the sixth Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.33–2.79 Å. In the seventh Na site, Na is bonded in a distorted pentagonal planar geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.42–2.70 Å. In the eighth Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.36–2.82 Å. In the ninth Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.31–2.73 Å. In the tenth Na site, Na is bonded in a distorted rectangular see-saw-like geometry to four O atoms. There are a spread of Na–O bond distances ranging from 2.28–2.53 Å. In the eleventh Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.38–2.70 Å. In the twelfth Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.31–2.70 Å. In the thirteenth Na site, Na is bonded in a distorted rectangular see-saw-like geometry to four O atoms. There are a spread of Na–O bond distances ranging from 2.29–2.51 Å. In the fourteenth Na site, Na is bonded in a 5-coordinate geometry to five O atoms. There are a spread of Na–O bond distances ranging from 2.44–2.83 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded to four O atoms to form FeO4 tetrahedra that share a cornercorner with one NaO6 pentagonal pyramid, corners with two NaO5 trigonal bipyramids, and edges with two NaO6 pentagonal pyramids. There are a spread of Fe–O bond distances ranging from 1.77–1.80 Å. In the second Fe site, Fe is bonded to four O atoms to form FeO4 tetrahedra that share a cornercorner with one NaO6 pentagonal pyramid, a cornercorner with one NaO5 trigonal bipyramid, and an edgeedge with one NaO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.78–1.81 Å. In the third Fe site, Fe is bonded to four O atoms to form FeO4 tetrahedra that share a cornercorner with one NaO6 pentagonal pyramid, corners with two NaO5 trigonal bipyramids, and edges with two NaO6 pentagonal pyramids. There are a spread of Fe–O bond distances ranging from 1.75–1.79 Å. In the fourth Fe site, Fe is bonded to four O atoms to form FeO4 tetrahedra that share a cornercorner with one NaO6 pentagonal pyramid, a cornercorner with one NaO5 trigonal bipyramid, and an edgeedge with one NaO5 trigonal bipyramid. There are a spread of Fe–O bond distances ranging from 1.79–1.81 Å. There are sixteen inequivalent O sites. In the first O site, O is bonded in a 6-coordinate geometry to five Na and one Fe atom. In the second O site, O is bonded to five Na and one Fe atom to form distorted ONa5Fe octahedra that share corners with two ONa5Fe octahedra, a cornercorner with one ONa4Fe trigonal bipyramid, and an edgeedge with one ONa5Fe octahedra. The corner-sharing octahedra tilt angles range from 38–40°. In the third O site, O is bonded in a 4-coordinate geometry to three Na and one Fe atom. In the fourth O site, O is bonded in a 6-coordinate geometry to five Na and one Fe atom. In the fifth O site, O is bonded to five Na and one Fe atom to form distorted ONa5Fe octahedra that share a cornercorner with one ONa5Fe octahedra, corners with two equivalent ONa4Fe trigonal bipyramids, an edgeedge with one ONa5Fe octahedra, an edgeedge with one ONa4Fe trigonal bipyramid, and a faceface with one ONa5Fe octahedra. The corner-sharing octahedral tilt angles are 39°. In the sixth O site, O is bonded to five Na and one Fe atom to form ONa5Fe octahedra that share a cornercorner with one ONa5Fe octahedra, a cornercorner with one ONa4Fe trigonal bipyramid, and edges with three ONa5Fe octahedra. The corner-sharing octahedral tilt angles are 39°. In the seventh O site, O is bonded in a 4-coordinate geometry to three Na and one Fe atom. In the eighth O site, O is bonded to four Na and one Fe atom to form distorted ONa4Fe trigonal bipyramids that share corners with four ONa5Fe octahedra, an edgeedge with one ONa5Fe octahedra, and an edgeedge with one ONa4Fe trigonal bipyramid. The corner-sharing octahedra tilt angles range from 42–89°. In the ninth O site, O is bonded to five Na and one Fe atom to form distorted ONa5Fe octahedra that share corners with two ONa5Fe octahedra, corners with two equivalent ONa4Fe trigonal bipyramids, an edgeedge with one ONa5Fe octahedra, and an edgeedge with one ONa4Fe trigonal bipyramid. The corner-sharing octahedra tilt angles range from 16–38°. In the tenth O site, O is bonded to four Na and one Fe atom to form distorted ONa4Fe trigonal bipyramids that share corners with four ONa5Fe octahedra, an edgeedge with one ONa5Fe octahedra, and an edgeedge with one ONa4Fe trigonal bipyramid. The corner-sharing octahedra tilt angles range from 25–90°. In the eleventh O site, O is bonded in a 5-coordinate geometry to four Na and one Fe atom. In the twelfth O site, O is bonded in a 1-coordinate geometry to four Na and one Fe atom. In the thirteenth O site, O is bonded in a 1-coordinate geometry to four Na and one Fe atom. In the fourteenth O site, O is bonded to five Na and one Fe atom to form distorted ONa5Fe octahedra that share corners with two ONa5Fe octahedra, corners with two ONa4Fe trigonal bipyramids, edges with two equivalent ONa5Fe octahedra, and a faceface with one ONa5Fe octahedra. The corner-sharing octahedra tilt angles range from 16–40°. In the fifteenth O site, O is bonded in a 6-coordinate geometry to five Na and one Fe atom. In the sixteenth O site, O is bonded in a 1-coordinate geometry to four Na and one Fe atom.