NaNiPO4 crystallizes in the orthorhombic Cmcm space group. Na(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with two equivalent Ni(1)O6 octahedra. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Ni(1), and one P(1) atom.
NaNiPO4 crystallizes in the orthorhombic Cmcm space group. Na(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. Both Na(1)-O(2) bond lengths are 2.24 Å. There are two shorter (2.38 Å) and two longer (2.61 Å) Na(1)-O(1) bond lengths. Ni(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form NiO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with two equivalent Ni(1)O6 octahedra. Both Ni(1)-O(2) bond lengths are 2.00 Å. All Ni(1)-O(1) bond lengths are 2.24 Å. P(1) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with six equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 42-52°. Both P(1)-O(1) bond lengths are 1.58 Å. Both P(1)-O(2) bond lengths are 1.53 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Ni(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Ni(1), and one P(1) atom.