Na5Cu(HO2)2 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted rectangular see-saw-like geometry to one O(2), one O(3), and two equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a distorted bent 150 degrees geometry to two equivalent O(3) atoms. In the third Na site, Na(3) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted face-sharing NaO6 octahedra. In the fourth Na site, Na(4) is bonded in a rectangular see-saw-like geometry to one O(2), one O(3), and two equivalent O(1) atoms. Cu(1) is bonded in a linear geometry to one O(2) and one O(3) atom. H(1) is bonded in a single-bond geometry to one O(1) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Na(1), two equivalent Na(3), two equivalent Na(4), and one H(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(3), two equivalent Na(4), and one Cu(1) atom. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), two equivalent Na(4), and one Cu(1) atom to form corner-sharing ONa5Cu octahedra. The corner-sharing octahedral tilt angles are 37°.
Na5Cu(HO2)2 crystallizes in the orthorhombic Pnma space group. There are four inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted rectangular see-saw-like geometry to one O(2), one O(3), and two equivalent O(1) atoms. The Na(1)-O(2) bond length is 2.26 Å. The Na(1)-O(3) bond length is 2.38 Å. Both Na(1)-O(1) bond lengths are 2.45 Å. In the second Na site, Na(2) is bonded in a distorted bent 150 degrees geometry to two equivalent O(3) atoms. There is one shorter (2.29 Å) and one longer (2.30 Å) Na(2)-O(3) bond length. In the third Na site, Na(3) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted face-sharing NaO6 octahedra. There is one shorter (2.41 Å) and one longer (2.57 Å) Na(3)-O(2) bond length. There are two shorter (2.47 Å) and two longer (2.61 Å) Na(3)-O(1) bond lengths. In the fourth Na site, Na(4) is bonded in a rectangular see-saw-like geometry to one O(2), one O(3), and two equivalent O(1) atoms. The Na(4)-O(2) bond length is 2.27 Å. The Na(4)-O(3) bond length is 2.29 Å. There is one shorter (2.38 Å) and one longer (2.40 Å) Na(4)-O(1) bond length. Cu(1) is bonded in a linear geometry to one O(2) and one O(3) atom. The Cu(1)-O(2) bond length is 1.80 Å. The Cu(1)-O(3) bond length is 1.83 Å. H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.98 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Na(1), two equivalent Na(3), two equivalent Na(4), and one H(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(3), two equivalent Na(4), and one Cu(1) atom. In the third O site, O(3) is bonded to one Na(1), two equivalent Na(2), two equivalent Na(4), and one Cu(1) atom to form corner-sharing ONa5Cu octahedra. The corner-sharing octahedral tilt angles are 37°.