K2Mg(CuO2)2 crystallizes in the monoclinic Pm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one Mg(1), two equivalent Cu(2), and four equivalent O(1) atoms. In the second K site, K(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Mg(1) is bonded in a rectangular see-saw-like geometry to one K(1), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. In the second Cu site, Cu(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1), two equivalent O(1), and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one K(2), two equivalent K(1), one Mg(1), one Cu(1), and one Cu(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(2), one Mg(1), one Cu(1), and one Cu(2) atom.
K2Mg(CuO2)2 crystallizes in the monoclinic Pm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 7-coordinate geometry to one Mg(1), two equivalent Cu(2), and four equivalent O(1) atoms. The K(1)-Mg(1) bond length is 2.86 Å. There is one shorter (2.72 Å) and one longer (2.90 Å) K(1)-Cu(2) bond length. There are two shorter (2.78 Å) and two longer (3.05 Å) K(1)-O(1) bond lengths. In the second K site, K(2) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(2) atoms. Both K(2)-O(1) bond lengths are 2.72 Å. Both K(2)-O(2) bond lengths are 2.84 Å. Mg(1) is bonded in a rectangular see-saw-like geometry to one K(1), two equivalent O(1), and two equivalent O(2) atoms. Both Mg(1)-O(1) bond lengths are 2.04 Å. Both Mg(1)-O(2) bond lengths are 2.01 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Cu(1)-O(1) bond lengths are 2.02 Å. Both Cu(1)-O(2) bond lengths are 2.03 Å. In the second Cu site, Cu(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent K(1), two equivalent O(1), and two equivalent O(2) atoms. Both Cu(2)-O(1) bond lengths are 1.93 Å. Both Cu(2)-O(2) bond lengths are 1.90 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 6-coordinate geometry to one K(2), two equivalent K(1), one Mg(1), one Cu(1), and one Cu(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one K(2), one Mg(1), one Cu(1), and one Cu(2) atom.