DOI: 10.17188/1294935
title: Materials Data on Na14Ni2O9 by Materials Project

description: Na14Ni2O9 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are seven inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share a cornercorner with one NiO4 tetrahedra, corners with fourteen NaO4 tetrahedra, an edgeedge with one NiO4 tetrahedra, and edges with four NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.34–2.44 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with two equivalent NiO4 tetrahedra, corners with twelve NaO4 tetrahedra, an edgeedge with one NiO4 tetrahedra, and edges with four NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.32–2.41 Å. In the third Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with two equivalent NiO4 tetrahedra, corners with twelve NaO4 tetrahedra, an edgeedge with one NiO4 tetrahedra, and edges with four NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.35–2.44 Å. In the fourth Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with three equivalent NiO4 tetrahedra, corners with ten NaO4 tetrahedra, and edges with six NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.33–2.39 Å. In the fifth Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share a cornercorner with one NiO4 tetrahedra, corners with fourteen NaO4 tetrahedra, an edgeedge with one NiO4 tetrahedra, and edges with four NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.34–2.46 Å. In the sixth Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share a cornercorner with one NiO4 tetrahedra, corners with fourteen NaO4 tetrahedra, an edgeedge with one NiO4 tetrahedra, and edges with four NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.32–2.43 Å. In the seventh Na1+ site, Na1+ is bonded to four O2- atoms to form NaO4 tetrahedra that share corners with two equivalent NiO4 tetrahedra, corners with twelve NaO4 tetrahedra, an edgeedge with one NiO4 tetrahedra, and edges with four NaO4 tetrahedra. There are a spread of Na–O bond distances ranging from 2.35–2.40 Å. Ni2+ is bonded to four O2- atoms to form NiO4 tetrahedra that share corners with twelve NaO4 tetrahedra and edges with six NaO4 tetrahedra. There are a spread of Ni–O bond distances ranging from 2.03–2.10 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to six Na1+ and one Ni2+ atom to form a mixture of distorted edge and corner-sharing ONa6Ni pentagonal bipyramids. In the second O2- site, O2- is bonded to six Na1+ and one Ni2+ atom to form a mixture of distorted edge and corner-sharing ONa6Ni pentagonal bipyramids. In the third O2- site, O2- is bonded in a 7-coordinate geometry to six Na1+ and one Ni2+ atom. In the fourth O2- site, O2- is bonded in a body-centered cubic geometry to eight Na1+ atoms. In the fifth O2- site, O2- is bonded to six Na1+ and one Ni2+ atom to form a mixture of distorted edge and corner-sharing ONa6Ni pentagonal bipyramids.