K2Li2FeO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. In the second K site, K(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(4) atoms. 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), and two equivalent O(3) atoms. 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 trigonal pyramids that share corners with two equivalent Fe(1)O4 tetrahedra and  an edgeedge with one Fe(1)O4 tetrahedra. Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 trigonal pyramids and  an edgeedge with one Li(2)O4 trigonal pyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(2), two equivalent K(1), 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 K(2), two equivalent K(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 K(1), one K(2), one Li(2), two equivalent Li(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent K(2), one Li(2), and one Fe(1) atom.
K2Li2FeO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 5-coordinate geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The K(1)-O(3) bond length is 2.89 Å. There is one shorter (2.81 Å) and one longer (2.84 Å) K(1)-O(1) bond length. There is one shorter (2.82 Å) and one longer (2.85 Å) K(1)-O(2) bond length. In the second K site, K(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(4) atoms. The K(2)-O(1) bond length is 2.83 Å. The K(2)-O(2) bond length is 2.70 Å. The K(2)-O(3) bond length is 2.79 Å. There is one shorter (2.80 Å) and one longer (2.86 Å) K(2)-O(4) 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), and two equivalent O(3) atoms. The Li(1)-O(1) bond length is 2.06 Å. The Li(1)-O(2) bond length is 1.99 Å. There is one shorter (1.94 Å) and one longer (2.16 Å) Li(1)-O(3) bond length. 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 trigonal pyramids that share corners with two equivalent Fe(1)O4 tetrahedra and  an edgeedge with one Fe(1)O4 tetrahedra. 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 2.07 Å. The Li(2)-O(4) bond length is 2.03 Å. Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form FeO4 tetrahedra that share corners with two equivalent Li(2)O4 trigonal pyramids and  an edgeedge with one Li(2)O4 trigonal pyramid. The Fe(1)-O(1) bond length is 1.87 Å. The Fe(1)-O(2) bond length is 1.84 Å. The Fe(1)-O(3) bond length is 1.87 Å. The Fe(1)-O(4) bond length is 1.78 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(2), two equivalent K(1), 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 K(2), two equivalent K(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 K(1), one K(2), one Li(2), two equivalent Li(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to two equivalent K(2), one Li(2), and one Fe(1) atom.