Na5CuSO2 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a linear geometry to four equivalent S(1) and two equivalent O(1) atoms. In the second Na site, Na(2) is bonded in a 2-coordinate geometry to two equivalent S(1) and two equivalent O(1) atoms. Cu(1) is bonded in a linear geometry to two equivalent O(1) atoms. S(1) is bonded to four equivalent Na(1) and eight equivalent Na(2) atoms to form SNa12 cuboctahedra that share corners with four equivalent S(1)Na12 cuboctahedra, faces with four equivalent S(1)Na12 cuboctahedra, and faces with eight equivalent O(1)Na5Cu octahedra. O(1) is bonded to one Na(1), four equivalent Na(2), and one Cu(1) atom to form ONa5Cu octahedra that share corners with six equivalent O(1)Na5Cu octahedra and faces with four equivalent S(1)Na12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-16°.
Na5CuSO2 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a linear geometry to four equivalent S(1) and two equivalent O(1) atoms. All Na(1)-S(1) bond lengths are 3.24 Å. Both Na(1)-O(1) bond lengths are 2.29 Å. In the second Na site, Na(2) is bonded in a 2-coordinate geometry to two equivalent S(1) and two equivalent O(1) atoms. Both Na(2)-S(1) bond lengths are 3.02 Å. Both Na(2)-O(1) bond lengths are 2.31 Å. Cu(1) is bonded in a linear geometry to two equivalent O(1) atoms. Both Cu(1)-O(1) bond lengths are 1.81 Å. S(1) is bonded to four equivalent Na(1) and eight equivalent Na(2) atoms to form SNa12 cuboctahedra that share corners with four equivalent S(1)Na12 cuboctahedra, faces with four equivalent S(1)Na12 cuboctahedra, and faces with eight equivalent O(1)Na5Cu octahedra. O(1) is bonded to one Na(1), four equivalent Na(2), and one Cu(1) atom to form ONa5Cu octahedra that share corners with six equivalent O(1)Na5Cu octahedra and faces with four equivalent S(1)Na12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-16°.