Na2Li2FeO4 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(3), two equivalent O(2), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, edges with four equivalent Na(2)O6 octahedra,  an edgeedge with one Li(2)O4 tetrahedra, and edges with two equivalent Fe(1)O4 tetrahedra. In the second Na site, Na(2) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with four equivalent Na(2)O6 octahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, edges with four equivalent Na(1)O6 octahedra,  an edgeedge with one Fe(1)O4 tetrahedra, and edges with two equivalent Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-18°. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate 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 two equivalent Na(2)O6 octahedra, corners with four equivalent Na(1)O6 octahedra, corners with two equivalent Fe(1)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-60°. Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted FeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Na(2)O6 octahedra, corners with two equivalent Li(2)O4 tetrahedra,  an edgeedge with one Na(2)O6 octahedra, 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 16-82°. 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 Fe(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Fe(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Fe(1) atom. In the fourth O site, O(4) is bonded to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Fe(1) atom to form distorted edge-sharing ONa3Li2Fe octahedra.
Na2Li2FeO4 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(3), two equivalent O(2), and two equivalent O(4) atoms to form distorted NaO6 octahedra that share corners with two equivalent Fe(1)O4 tetrahedra, corners with four equivalent Li(2)O4 tetrahedra, edges with two equivalent Na(1)O6 octahedra, edges with four equivalent Na(2)O6 octahedra,  an edgeedge with one Li(2)O4 tetrahedra, and edges with two equivalent Fe(1)O4 tetrahedra. The Na(1)-O(1) bond length is 2.35 Å. The Na(1)-O(3) bond length is 2.39 Å. There is one shorter (2.36 Å) and one longer (2.62 Å) Na(1)-O(2) bond length. There is one shorter (2.49 Å) and one longer (2.51 Å) Na(1)-O(4) bond length. In the second Na site, Na(2) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form distorted NaO6 octahedra that share corners with four equivalent Na(2)O6 octahedra, corners with two equivalent Li(2)O4 tetrahedra, corners with four equivalent Fe(1)O4 tetrahedra, edges with four equivalent Na(1)O6 octahedra,  an edgeedge with one Fe(1)O4 tetrahedra, and edges with two equivalent Li(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 16-18°. The Na(2)-O(2) bond length is 2.47 Å. The Na(2)-O(4) bond length is 2.55 Å. There is one shorter (2.45 Å) and one longer (2.77 Å) Na(2)-O(1) bond length. There is one shorter (2.67 Å) and one longer (2.78 Å) Na(2)-O(3) bond length. There are two inequivalent Li sites. In the first Li site, Li(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Li(1)-O(1) bond length is 1.88 Å. The Li(1)-O(2) bond length is 2.29 Å. The Li(1)-O(3) bond length is 1.98 Å. The Li(1)-O(4) bond length is 2.04 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 two equivalent Na(2)O6 octahedra, corners with four equivalent Na(1)O6 octahedra, corners with two equivalent Fe(1)O4 tetrahedra,  an edgeedge with one Na(1)O6 octahedra, edges with two equivalent Na(2)O6 octahedra, and  an edgeedge with one Fe(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 24-60°. The Li(2)-O(1) bond length is 1.97 Å. The Li(2)-O(2) bond length is 1.99 Å. The Li(2)-O(3) bond length is 1.97 Å. The Li(2)-O(4) bond length is 1.96 Å. Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form distorted FeO4 tetrahedra that share corners with two equivalent Na(1)O6 octahedra, corners with four equivalent Na(2)O6 octahedra, corners with two equivalent Li(2)O4 tetrahedra,  an edgeedge with one Na(2)O6 octahedra, 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 16-82°. The Fe(1)-O(1) bond length is 1.83 Å. The Fe(1)-O(2) bond length is 1.83 Å. The Fe(1)-O(3) bond length is 1.82 Å. The Fe(1)-O(4) bond length is 1.84 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 Fe(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Fe(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Na(1), two equivalent Na(2), one Li(1), one Li(2), and one Fe(1) atom. In the fourth O site, O(4) is bonded to one Na(2), two equivalent Na(1), one Li(1), one Li(2), and one Fe(1) atom to form distorted edge-sharing ONa3Li2Fe octahedra.