Materials Data on Na3NiO3 by Materials Project

Na3NiO3 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.24–2.94 Å. In the second Na1+ site, Na1+ is bonded to four O2- atoms to form distorted corner-sharing NaO4 tetrahedra. There are two shorter (2.29 Å) and two longer (2.34 Å) Na–O bond lengths. Ni3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There is two shorter (1.83 Å) and two longer (1.86 Å) Ni–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to four Na1+ and two equivalent Ni3+ atoms. In the second O2- site, O2- is bonded in a 5-coordinate geometry to five Na1+ and one Ni3+ atom.