Materials Data on NaNiPO11 by Materials Project
NaNiO7PO4 crystallizes in the tetragonal P4_2/mmc space group. The structure is three-dimensional and consists of two phosphoric acid molecules and one NaNiO7 framework. In the NaNiO7 framework, Na is bonded to six O atoms to form NaO6 octahedra that share corners with two equivalent NaO6 octahedra and edges with two equivalent NiO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.28 Å) and two longer (2.44 Å) Na–O bond lengths. Ni is bonded to six O atoms to form NiO6 octahedra that share edges with two equivalent NaO6 octahedra. All Ni–O bond lengths are 1.83 Å. There are three inequivalent O sites. In the first O site, O is bonded in a single-bond geometry to one Ni atom. In the second O site, O is bonded in a water-like geometry to one Na and one Ni atom. In the third O site, O is bonded in a linear geometry to two equivalent Na atoms.