Na2Li2CoO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra,  an edgeedge with one Li(2)O4 tetrahedra, and edges with two equivalent Co(1)O4 tetrahedra. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted LiO4 tetrahedra that share corners with four equivalent Na(1)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and  an edgeedge with one Co(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-38°. Co(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form CoO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-55°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Co(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Co(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Co(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Co(1) atom.
Na2Li2CoO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra,  an edgeedge with one Li(2)O4 tetrahedra, and edges with two equivalent Co(1)O4 tetrahedra. The Na(1)-O(1) bond length is 2.34 Å. The Na(1)-O(2) bond length is 2.35 Å. Both Na(1)-O(3) bond lengths are 2.54 Å. There is one shorter (2.39 Å) and one longer (2.58 Å) Na(1)-O(4) bond length. In the second Na site, Na(2) is bonded in a 6-coordinate geometry to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms. The Na(2)-O(3) bond length is 2.56 Å. The Na(2)-O(4) bond length is 2.57 Å. There is one shorter (2.58 Å) and one longer (2.68 Å) Na(2)-O(1) bond length. There is one shorter (2.54 Å) and one longer (2.91 Å) Na(2)-O(2) bond length. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Li(1)-O(1) bond length is 1.89 Å. The Li(1)-O(2) bond length is 2.00 Å. The Li(1)-O(3) bond length is 2.00 Å. The Li(1)-O(4) bond length is 2.08 Å. In the second Li site, Li(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted LiO4 tetrahedra that share corners with four equivalent Na(1)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, and  an edgeedge with one Co(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 27-38°. The Li(2)-O(1) bond length is 1.96 Å. The Li(2)-O(2) bond length is 1.93 Å. The Li(2)-O(3) bond length is 1.97 Å. The Li(2)-O(4) bond length is 2.04 Å. Co(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form CoO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with two equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, and  an edgeedge with one Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-55°. The Co(1)-O(1) bond length is 1.82 Å. The Co(1)-O(2) bond length is 1.80 Å. The Co(1)-O(3) bond length is 1.81 Å. The Co(1)-O(4) bond length is 1.81 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Co(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Co(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Co(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Co(1) atom.