Na2Ni(HPO3)2 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one H(2), one O(2), two equivalent O(1), and two equivalent O(3) atoms. In the second Na site, Na(2) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. Ni(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent P(1)HO3 tetrahedra and corners with three equivalent P(2)HO3 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one H(2), one O(4), and two equivalent O(1) atoms to form distorted PHO3 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the second P site, P(2) is bonded to one H(1), one O(2), and two equivalent O(3) atoms to form distorted PHO3 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-44°. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one P(2) atom. In the second H site, H(2) is bonded in a bent 150 degrees geometry to one Na(1) and one P(1) atom. There are four inequivalent O sites. In the first O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Ni(1), and one P(2) atom. In the second O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Ni(1), and one P(2) atom. In the third O site, O(4) is bonded in a 3-coordinate geometry to one Na(2), one Ni(1), and one P(1) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Ni(1), and one P(1) atom.
Na2Ni(HPO3)2 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 6-coordinate geometry to one H(2), one O(2), two equivalent O(1), and two equivalent O(3) atoms. The Na(1)-H(2) bond length is 2.53 Å. The Na(1)-O(2) bond length is 2.40 Å. Both Na(1)-O(1) bond lengths are 2.37 Å. Both Na(1)-O(3) bond lengths are 2.42 Å. In the second Na site, Na(2) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and four equivalent O(3) atoms. The Na(2)-O(4) bond length is 2.31 Å. Both Na(2)-O(1) bond lengths are 2.66 Å. Both Na(2)-O(2) bond lengths are 2.72 Å. There are two shorter (2.68 Å) and two longer (2.79 Å) Na(2)-O(3) bond lengths. Ni(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form NiO6 octahedra that share corners with three equivalent P(1)HO3 tetrahedra and corners with three equivalent P(2)HO3 tetrahedra. The Ni(1)-O(2) bond length is 2.11 Å. The Ni(1)-O(4) bond length is 2.09 Å. Both Ni(1)-O(1) bond lengths are 2.08 Å. Both Ni(1)-O(3) bond lengths are 2.13 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one H(2), one O(4), and two equivalent O(1) atoms to form distorted PHO3 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. The P(1)-H(2) bond length is 1.40 Å. The P(1)-O(4) bond length is 1.54 Å. Both P(1)-O(1) bond lengths are 1.54 Å. In the second P site, P(2) is bonded to one H(1), one O(2), and two equivalent O(3) atoms to form distorted PHO3 tetrahedra that share corners with three equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-44°. The P(2)-H(1) bond length is 1.42 Å. The P(2)-O(2) bond length is 1.54 Å. Both P(2)-O(3) bond lengths are 1.54 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one P(2) atom. In the second H site, H(2) is bonded in a bent 150 degrees geometry to one Na(1) and one P(1) atom. There are four inequivalent O sites. In the first O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Ni(1), and one P(2) atom. In the second O site, O(3) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Na(2), one Ni(1), and one P(2) atom. In the third O site, O(4) is bonded in a 3-coordinate geometry to one Na(2), one Ni(1), and one P(1) atom. In the fourth O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Ni(1), and one P(1) atom.