DOI: 10.17188/1296146
title: Materials Data on Na5Ni9O16 by Materials Project

description: Na5Ni9O16 crystallizes in the monoclinic P2/m space group. The structure is three-dimensional. there are three inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six NiO6 octahedra, edges with three NaO6 octahedra, and edges with seven NiO6 octahedra. The corner-sharing octahedra tilt angles range from 9–16°. There are four shorter (2.28 Å) and two longer (2.37 Å) Na–O bond lengths. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form distorted NaO6 octahedra that share corners with six NiO6 octahedra, edges with six NaO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedral tilt angles are 13°. There are four shorter (2.26 Å) and two longer (2.29 Å) Na–O bond lengths. In the third Na1+ site, Na1+ is bonded to six O2- atoms to form NaO6 octahedra that share corners with six NiO6 octahedra, edges with five NaO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 9–14°. There are a spread of Na–O bond distances ranging from 2.31–2.39 Å. There are six inequivalent Ni3+ sites. In the first Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with four equivalent NaO6 octahedra, edges with six NaO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 9–12°. There are a spread of Ni–O bond distances ranging from 1.93–2.02 Å. In the second Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent NaO6 octahedra, edges with two equivalent NaO6 octahedra, and edges with eight NiO6 octahedra. The corner-sharing octahedral tilt angles are 14°. There is two shorter (1.89 Å) and four longer (1.91 Å) Ni–O bond length. In the third Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent NiO6 octahedra, corners with four NaO6 octahedra, edges with four NaO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 13–17°. There are two shorter (2.02 Å) and four longer (2.10 Å) Ni–O bond lengths. In the fourth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with two equivalent NiO6 octahedra, corners with four equivalent NaO6 octahedra, and edges with eight NiO6 octahedra. The corner-sharing octahedra tilt angles range from 14–15°. There are four shorter (1.94 Å) and two longer (2.20 Å) Ni–O bond lengths. In the fifth Ni3+ site, Ni3+ is bonded to six O2- atoms to form NiO6 octahedra that share corners with six NaO6 octahedra, edges with six NaO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 9–13°. There are four shorter (1.94 Å) and two longer (2.08 Å) Ni–O bond lengths. In the sixth Ni3+ site, Ni3+ is bonded to six O2- atoms to form distorted NiO6 octahedra that share corners with six NiO6 octahedra, edges with two equivalent NaO6 octahedra, and edges with six NiO6 octahedra. The corner-sharing octahedra tilt angles range from 15–17°. There are four shorter (2.16 Å) and two longer (2.17 Å) Ni–O bond lengths. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded to three Na1+ and three Ni3+ atoms to form ONa3Ni3 octahedra that share corners with four equivalent ONa3Ni3 octahedra, corners with two equivalent ONaNi4 square pyramids, edges with seven ONa3Ni3 octahedra, and edges with five ONaNi4 square pyramids. The corner-sharing octahedra tilt angles range from 0–8°. In the second O2- site, O2- is bonded to one Na1+ and four Ni3+ atoms to form ONaNi4 square pyramids that share corners with two equivalent ONa3Ni3 octahedra, corners with five ONaNi4 square pyramids, an edgeedge with one ONa3Ni3 octahedra, and edges with five ONaNi4 square pyramids. The corner-sharing octahedral tilt angles are 3°. In the third O2- site, O2- is bonded to three Na1+ and three Ni3+ atoms to form ONa3Ni3 octahedra that share corners with two equivalent ONa3Ni3 octahedra, corners with four equivalent ONa2Ni3 square pyramids, edges with ten ONa3Ni3 octahedra, and edges with two equivalent ONa2Ni3 square pyramids. The corner-sharing octahedral tilt angles are 0°. In the fourth O2- site, O2- is bonded to two Na1+ and three Ni3+ atoms to form ONa2Ni3 square pyramids that share corners with two equivalent ONa3Ni3 octahedra, corners with five ONaNi4 square pyramids, edges with five ONa3Ni3 octahedra, and edges with three ONaNi4 square pyramids. The corner-sharing octahedra tilt angles range from 2–5°. In the fifth O2- site, O2- is bonded in a rectangular see-saw-like geometry to four Ni3+ atoms.