DOI: 10.17188/1294941
title: Materials Data on Na8FeO6 by Materials Project

description: Na8FeO6 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are eight inequivalent Na sites. In the first Na site, Na is bonded to four O atoms to form NaO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with nine NaO4 tetrahedra, a cornercorner with one NaO4 trigonal pyramid, edges with four NaO4 tetrahedra, and an edgeedge with one NaO4 trigonal pyramid. There are a spread of Na–O bond distances ranging from 2.31–2.47 Å. In the second Na site, Na is bonded to four O atoms to form distorted NaO4 tetrahedra that share corners with eleven NaO4 tetrahedra, corners with three equivalent NaO4 trigonal pyramids, an edgeedge with one FeO4 tetrahedra, and edges with three NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.29–2.47 Å. In the third Na site, Na is bonded to four O atoms to form NaO4 tetrahedra that share corners with three equivalent FeO4 tetrahedra, corners with seven NaO4 tetrahedra, corners with two equivalent NaO4 trigonal pyramids, and edges with three NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.32–2.43 Å. In the fourth Na site, Na is bonded to four O atoms to form NaO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with nine NaO4 tetrahedra, a cornercorner with one NaO4 trigonal pyramid, edges with four NaO4 tetrahedra, and an edgeedge with one NaO4 trigonal pyramid. There are a spread of Na–O bond distances ranging from 2.31–2.42 Å. In the fifth Na site, Na is bonded to four O atoms to form distorted NaO4 tetrahedra that share corners with eleven NaO4 tetrahedra, corners with three equivalent NaO4 trigonal pyramids, an edgeedge with one FeO4 tetrahedra, and edges with three NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.29–2.46 Å. In the sixth Na site, Na is bonded to four O atoms to form distorted NaO4 trigonal pyramids that share corners with fourteen NaO4 tetrahedra, an edgeedge with one FeO4 tetrahedra, and edges with three NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.32–2.52 Å. In the seventh Na site, Na is bonded to four O atoms to form NaO4 tetrahedra that share corners with two equivalent FeO4 tetrahedra, corners with eight NaO4 tetrahedra, corners with two equivalent NaO4 trigonal pyramids, edges with four NaO4 tetrahedra, and an edgeedge with one NaO4 trigonal pyramid. There are a spread of Na–O bond distances ranging from 2.30–2.39 Å. In the eighth Na site, Na is bonded to four O atoms to form NaO4 tetrahedra that share corners with three equivalent FeO4 tetrahedra, corners with seven NaO4 tetrahedra, corners with two equivalent NaO4 trigonal pyramids, and edges with three NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.33–2.43 Å. Fe is bonded to four O atoms to form FeO4 tetrahedra that share corners with twelve NaO4 tetrahedra, edges with two NaO4 tetrahedra, and an edgeedge with one NaO4 trigonal pyramid. There are a spread of Fe–O bond distances ranging from 1.85–1.94 Å. There are six inequivalent O sites. In the first O site, O is bonded to four Na and one Fe atom to form ONa4Fe trigonal bipyramids that share corners with two ONa7 pentagonal bipyramids, corners with six ONa4Fe trigonal bipyramids, and edges with two ONa7 pentagonal bipyramids. In the second O site, O is bonded to seven Na atoms to form distorted ONa7 pentagonal bipyramids that share corners with three ONa4Fe trigonal bipyramids, edges with three equivalent ONa7 pentagonal bipyramids, and edges with three ONa4Fe trigonal bipyramids. In the third O site, O is bonded in a 7-coordinate geometry to six Na and one Fe atom. In the fourth O site, O is bonded to four Na and one Fe atom to form ONa4Fe trigonal bipyramids that share corners with two ONa7 pentagonal bipyramids, corners with six ONa4Fe trigonal bipyramids, and edges with two ONa7 pentagonal bipyramids. In the fifth O site, O is bonded to four Na and one Fe atom to form ONa4Fe trigonal bipyramids that share corners with two ONa7 pentagonal bipyramids, corners with six ONa4Fe trigonal bipyramids, and edges with two ONa7 pentagonal bipyramids. In the sixth O site, O is bonded to seven Na atoms to form distorted ONa7 pentagonal bipyramids that share corners with three ONa4Fe trigonal bipyramids, edges with three equivalent ONa7 pentagonal bipyramids, and edges with three ONa4Fe trigonal bipyramids.