Na6CuO4 is alpha Pu-derived structured and crystallizes in the monoclinic Cc space group. There are six inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(4) atoms. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. In the third Na site, Na(3) is bonded in a 3-coordinate geometry to one O(2), two equivalent O(1), and two equivalent O(4) atoms. In the fourth Na site, Na(4) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted NaO4 trigonal pyramids that share corners with two equivalent Cu(1)O4 tetrahedra, corners with four equivalent Na(6)O4 trigonal pyramids, and  an edgeedge with one Cu(1)O4 tetrahedra. In the fifth Na site, Na(5) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. In the sixth Na site, Na(6) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted NaO4 trigonal pyramids that share corners with two equivalent Cu(1)O4 tetrahedra, corners with two equivalent Na(6)O4 trigonal pyramids, corners with four equivalent Na(4)O4 trigonal pyramids, and  an edgeedge with one Cu(1)O4 tetrahedra. Cu(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form CuO4 tetrahedra that share corners with two equivalent Na(4)O4 trigonal pyramids, corners with two equivalent Na(6)O4 trigonal pyramids,  an edgeedge with one Na(4)O4 trigonal pyramid, and  an edgeedge with one Na(6)O4 trigonal pyramid. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 8-coordinate geometry to one Na(1), one Na(4), one Na(6), two equivalent Na(2), two equivalent Na(5), and one Cu(1) atom. In the second O site, O(4) is bonded in a 8-coordinate geometry to one Na(2), one Na(4), one Na(5), two equivalent Na(1), two equivalent Na(3), and one Cu(1) atom. In the third O site, O(1) is bonded in a 8-coordinate geometry to one Na(2), one Na(4), one Na(5), two equivalent Na(3), two equivalent Na(6), and one Cu(1) atom. In the fourth O site, O(2) is bonded in a 7-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(4), one Na(5), one Na(6), and one Cu(1) atom.
Na6CuO4 is alpha Pu-derived structured and crystallizes in the monoclinic Cc space group. There are six inequivalent Na sites. In the first Na site, Na(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), and two equivalent O(4) atoms. The Na(1)-O(2) bond length is 2.66 Å. The Na(1)-O(3) bond length is 2.37 Å. There is one shorter (2.36 Å) and one longer (2.39 Å) Na(1)-O(4) bond length. In the second Na site, Na(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. The Na(2)-O(1) bond length is 2.52 Å. The Na(2)-O(2) bond length is 2.33 Å. The Na(2)-O(4) bond length is 2.75 Å. There is one shorter (2.47 Å) and one longer (2.63 Å) Na(2)-O(3) bond length. In the third Na site, Na(3) is bonded in a 3-coordinate geometry to one O(2), two equivalent O(1), and two equivalent O(4) atoms. The Na(3)-O(2) bond length is 2.37 Å. There is one shorter (2.47 Å) and one longer (2.65 Å) Na(3)-O(1) bond length. There is one shorter (2.39 Å) and one longer (2.80 Å) Na(3)-O(4) bond length. In the fourth Na site, Na(4) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted NaO4 trigonal pyramids that share corners with two equivalent Cu(1)O4 tetrahedra, corners with four equivalent Na(6)O4 trigonal pyramids, and  an edgeedge with one Cu(1)O4 tetrahedra. The Na(4)-O(1) bond length is 2.36 Å. The Na(4)-O(2) bond length is 2.56 Å. The Na(4)-O(3) bond length is 2.34 Å. The Na(4)-O(4) bond length is 2.36 Å. In the fifth Na site, Na(5) is bonded in a 3-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. The Na(5)-O(1) bond length is 2.82 Å. The Na(5)-O(2) bond length is 2.36 Å. The Na(5)-O(4) bond length is 2.40 Å. There is one shorter (2.44 Å) and one longer (2.83 Å) Na(5)-O(3) bond length. In the sixth Na site, Na(6) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted NaO4 trigonal pyramids that share corners with two equivalent Cu(1)O4 tetrahedra, corners with two equivalent Na(6)O4 trigonal pyramids, corners with four equivalent Na(4)O4 trigonal pyramids, and  an edgeedge with one Cu(1)O4 tetrahedra. The Na(6)-O(2) bond length is 2.52 Å. The Na(6)-O(3) bond length is 2.33 Å. There is one shorter (2.32 Å) and one longer (2.34 Å) Na(6)-O(1) bond length. Cu(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form CuO4 tetrahedra that share corners with two equivalent Na(4)O4 trigonal pyramids, corners with two equivalent Na(6)O4 trigonal pyramids,  an edgeedge with one Na(4)O4 trigonal pyramid, and  an edgeedge with one Na(6)O4 trigonal pyramid. The Cu(1)-O(1) bond length is 2.01 Å. The Cu(1)-O(2) bond length is 1.97 Å. The Cu(1)-O(3) bond length is 2.06 Å. The Cu(1)-O(4) bond length is 2.08 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 8-coordinate geometry to one Na(1), one Na(4), one Na(6), two equivalent Na(2), two equivalent Na(5), and one Cu(1) atom. In the second O site, O(4) is bonded in a 8-coordinate geometry to one Na(2), one Na(4), one Na(5), two equivalent Na(1), two equivalent Na(3), and one Cu(1) atom. In the third O site, O(1) is bonded in a 8-coordinate geometry to one Na(2), one Na(4), one Na(5), two equivalent Na(3), two equivalent Na(6), and one Cu(1) atom. In the fourth O site, O(2) is bonded in a 7-coordinate geometry to one Na(1), one Na(2), one Na(3), one Na(4), one Na(5), one Na(6), and one Cu(1) atom.