K2Mg(CoO2)2 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), and two equivalent O(4) 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 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a trigonal planar geometry to one O(1) and two equivalent O(3) atoms. In the second Co site, Co(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form distorted corner-sharing CoO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded to one K(1), two equivalent K(2), one Co(1), and one Co(2) atom to form distorted OK3Co2 trigonal bipyramids that share corners with two equivalent O(1)K3Co2 trigonal bipyramids and corners with three equivalent O(4)K2Mg2Co trigonal bipyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent K(2), one Mg(1), and two equivalent Co(2) atoms. In the third O site, O(3) is bonded in a 5-coordinate geometry to one K(1), two equivalent Mg(1), and two equivalent Co(1) atoms. In the fourth O site, O(4) is bonded to two equivalent K(1), two equivalent Mg(1), and one Co(2) atom to form distorted OK2Mg2Co trigonal bipyramids that share corners with three equivalent O(1)K3Co2 trigonal bipyramids and edges with two equivalent O(4)K2Mg2Co trigonal bipyramids.
K2Mg(CoO2)2 crystallizes in the monoclinic Cm space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), and two equivalent O(4) atoms. The K(1)-O(1) bond length is 2.67 Å. The K(1)-O(3) bond length is 2.97 Å. Both K(1)-O(4) bond lengths are 2.66 Å. 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 2.76 Å. Both K(2)-O(2) bond lengths are 2.75 Å. Mg(1) is bonded in a 5-coordinate geometry to one O(2), two equivalent O(3), and two equivalent O(4) atoms. The Mg(1)-O(2) bond length is 2.04 Å. Both Mg(1)-O(3) bond lengths are 2.35 Å. Both Mg(1)-O(4) bond lengths are 2.00 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a trigonal planar geometry to one O(1) and two equivalent O(3) atoms. The Co(1)-O(1) bond length is 1.80 Å. Both Co(1)-O(3) bond lengths are 1.98 Å. In the second Co site, Co(2) is bonded to one O(1), one O(4), and two equivalent O(2) atoms to form distorted corner-sharing CoO4 tetrahedra. The Co(2)-O(1) bond length is 1.97 Å. The Co(2)-O(4) bond length is 2.08 Å. Both Co(2)-O(2) bond lengths are 2.00 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one K(1), two equivalent K(2), one Co(1), and one Co(2) atom to form distorted OK3Co2 trigonal bipyramids that share corners with two equivalent O(1)K3Co2 trigonal bipyramids and corners with three equivalent O(4)K2Mg2Co trigonal bipyramids. In the second O site, O(2) is bonded in a 5-coordinate geometry to two equivalent K(2), one Mg(1), and two equivalent Co(2) atoms. In the third O site, O(3) is bonded in a 5-coordinate geometry to one K(1), two equivalent Mg(1), and two equivalent Co(1) atoms. In the fourth O site, O(4) is bonded to two equivalent K(1), two equivalent Mg(1), and one Co(2) atom to form distorted OK2Mg2Co trigonal bipyramids that share corners with three equivalent O(1)K3Co2 trigonal bipyramids and edges with two equivalent O(4)K2Mg2Co trigonal bipyramids.