Na3(CoO2)4 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted NaO6 pentagonal pyramids that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Co(2)O6 octahedra, edges with three equivalent Co(1)O6 octahedra, edges with three equivalent Co(2)O6 octahedra, and edges with six equivalent Na(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 9-13°. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(4) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form CoO6 octahedra that share corners with three equivalent Na(1)O6 pentagonal pyramids, edges with two equivalent Co(1)O6 octahedra, edges with four equivalent Co(2)O6 octahedra, and edges with three equivalent Na(1)O6 pentagonal pyramids. In the second Co site, Co(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share corners with three equivalent Na(1)O6 pentagonal pyramids, edges with two equivalent Co(2)O6 octahedra, edges with four equivalent Co(1)O6 octahedra, and edges with three equivalent Na(1)O6 pentagonal pyramids. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Na(1), one Co(2), and two equivalent Co(1) atoms to form ONa3Co3 octahedra that share corners with two equivalent O(2)Na3Co3 octahedra, corners with four equivalent O(1)Na3Co3 octahedra, corners with three equivalent O(4)Na2Co3 square pyramids, edges with two equivalent O(1)Na3Co3 octahedra, edges with four equivalent O(2)Na3Co3 octahedra,  an edgeedge with one O(4)Na2Co3 square pyramid, and  a faceface with one O(2)Na3Co3 octahedra. The corner-sharing octahedral tilt angles range from 41-43°. In the second O site, O(2) is bonded to three equivalent Na(1), one Co(1), and two equivalent Co(2) atoms to form ONa3Co3 octahedra that share corners with two equivalent O(1)Na3Co3 octahedra, corners with four equivalent O(2)Na3Co3 octahedra, edges with two equivalent O(2)Na3Co3 octahedra, edges with four equivalent O(1)Na3Co3 octahedra, edges with two equivalent O(4)Na2Co3 square pyramids, and  a faceface with one O(1)Na3Co3 octahedra. The corner-sharing octahedral tilt angles range from 41-44°. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Na(2), one Co(1), and two equivalent Co(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Na(2), one Co(2), and two equivalent Co(1) atoms to form ONa2Co3 square pyramids that share corners with three equivalent O(1)Na3Co3 octahedra, corners with two equivalent O(4)Na2Co3 square pyramids,  an edgeedge with one O(1)Na3Co3 octahedra, edges with two equivalent O(2)Na3Co3 octahedra, and edges with three equivalent O(4)Na2Co3 square pyramids. The corner-sharing octahedral tilt angles range from 1-4°.
Na3(CoO2)4 crystallizes in the orthorhombic Imm2 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form distorted NaO6 pentagonal pyramids that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Co(2)O6 octahedra, edges with three equivalent Co(1)O6 octahedra, edges with three equivalent Co(2)O6 octahedra, and edges with six equivalent Na(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 9-13°. There are two shorter (2.39 Å) and one longer (2.40 Å) Na(1)-O(1) bond length. There are two shorter (2.38 Å) and one longer (2.39 Å) Na(1)-O(2) bond length. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to two equivalent O(3) and four equivalent O(4) atoms. Both Na(2)-O(3) bond lengths are 2.48 Å. All Na(2)-O(4) bond lengths are 2.42 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), one O(3), two equivalent O(1), and two equivalent O(4) atoms to form CoO6 octahedra that share corners with three equivalent Na(1)O6 pentagonal pyramids, edges with two equivalent Co(1)O6 octahedra, edges with four equivalent Co(2)O6 octahedra, and edges with three equivalent Na(1)O6 pentagonal pyramids. The Co(1)-O(2) bond length is 2.03 Å. The Co(1)-O(3) bond length is 1.95 Å. Both Co(1)-O(1) bond lengths are 2.09 Å. Both Co(1)-O(4) bond lengths are 2.04 Å. In the second Co site, Co(2) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share corners with three equivalent Na(1)O6 pentagonal pyramids, edges with two equivalent Co(2)O6 octahedra, edges with four equivalent Co(1)O6 octahedra, and edges with three equivalent Na(1)O6 pentagonal pyramids. The Co(2)-O(1) bond length is 1.98 Å. The Co(2)-O(4) bond length is 1.96 Å. Both Co(2)-O(2) bond lengths are 2.07 Å. Both Co(2)-O(3) bond lengths are 1.99 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to three equivalent Na(1), one Co(2), and two equivalent Co(1) atoms to form ONa3Co3 octahedra that share corners with two equivalent O(2)Na3Co3 octahedra, corners with four equivalent O(1)Na3Co3 octahedra, corners with three equivalent O(4)Na2Co3 square pyramids, edges with two equivalent O(1)Na3Co3 octahedra, edges with four equivalent O(2)Na3Co3 octahedra,  an edgeedge with one O(4)Na2Co3 square pyramid, and  a faceface with one O(2)Na3Co3 octahedra. The corner-sharing octahedral tilt angles range from 41-43°. In the second O site, O(2) is bonded to three equivalent Na(1), one Co(1), and two equivalent Co(2) atoms to form ONa3Co3 octahedra that share corners with two equivalent O(1)Na3Co3 octahedra, corners with four equivalent O(2)Na3Co3 octahedra, edges with two equivalent O(2)Na3Co3 octahedra, edges with four equivalent O(1)Na3Co3 octahedra, edges with two equivalent O(4)Na2Co3 square pyramids, and  a faceface with one O(1)Na3Co3 octahedra. The corner-sharing octahedral tilt angles range from 41-44°. In the third O site, O(3) is bonded in a distorted see-saw-like geometry to one Na(2), one Co(1), and two equivalent Co(2) atoms. In the fourth O site, O(4) is bonded to two equivalent Na(2), one Co(2), and two equivalent Co(1) atoms to form ONa2Co3 square pyramids that share corners with three equivalent O(1)Na3Co3 octahedra, corners with two equivalent O(4)Na2Co3 square pyramids,  an edgeedge with one O(1)Na3Co3 octahedra, edges with two equivalent O(2)Na3Co3 octahedra, and edges with three equivalent O(4)Na2Co3 square pyramids. The corner-sharing octahedral tilt angles range from 1-4°.