K2CoO2 crystallizes in the monoclinic P2_1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to one O(3), one O(4), and two equivalent O(1) atoms. In the second K site, K(2) is bonded in a 4-coordinate geometry to one O(3), one O(4), and two equivalent O(2) atoms. In the third K site, K(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(4) atoms. In the fourth K site, K(4) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted trigonal planar geometry to one O(1), one O(2), and one O(4) atom. In the second Co site, Co(2) is bonded in a distorted trigonal planar geometry to one O(1), one O(2), and one O(3) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded to one K(3), one K(4), two equivalent K(1), one Co(1), and one Co(2) atom to form a mixture of distorted edge and corner-sharing OK4Co2 octahedra. The corner-sharing octahedral tilt angles are 63°. In the second O site, O(2) is bonded to one K(3), one K(4), two equivalent K(2), one Co(1), and one Co(2) atom to form a mixture of distorted edge and corner-sharing OK4Co2 octahedra. The corner-sharing octahedral tilt angles are 63°. In the third O site, O(3) is bonded in a 6-coordinate geometry to one K(1), one K(2), one K(3), two equivalent K(4), and one Co(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one K(1), one K(2), one K(4), two equivalent K(3), and one Co(1) atom.
K2CoO2 crystallizes in the monoclinic P2_1 space group. There are four inequivalent K sites. In the first K site, K(1) is bonded in a 4-coordinate geometry to one O(3), one O(4), and two equivalent O(1) atoms. The K(1)-O(3) bond length is 2.64 Å. The K(1)-O(4) bond length is 2.66 Å. There is one shorter (2.84 Å) and one longer (2.86 Å) K(1)-O(1) bond length. In the second K site, K(2) is bonded in a 4-coordinate geometry to one O(3), one O(4), and two equivalent O(2) atoms. The K(2)-O(3) bond length is 2.66 Å. The K(2)-O(4) bond length is 2.64 Å. There is one shorter (2.84 Å) and one longer (2.86 Å) K(2)-O(2) bond length. In the third K site, K(3) 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(3)-O(1) bond length is 2.85 Å. The K(3)-O(2) bond length is 2.79 Å. The K(3)-O(3) bond length is 3.09 Å. There is one shorter (2.75 Å) and one longer (2.80 Å) K(3)-O(4) bond length. In the fourth K site, K(4) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), and two equivalent O(3) atoms. The K(4)-O(1) bond length is 2.79 Å. The K(4)-O(2) bond length is 2.84 Å. The K(4)-O(4) bond length is 3.10 Å. There is one shorter (2.75 Å) and one longer (2.80 Å) K(4)-O(3) bond length. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted trigonal planar geometry to one O(1), one O(2), and one O(4) atom. The Co(1)-O(1) bond length is 1.98 Å. The Co(1)-O(2) bond length is 1.89 Å. The Co(1)-O(4) bond length is 1.77 Å. In the second Co site, Co(2) is bonded in a distorted trigonal planar geometry to one O(1), one O(2), and one O(3) atom. The Co(2)-O(1) bond length is 1.89 Å. The Co(2)-O(2) bond length is 1.98 Å. The Co(2)-O(3) bond length is 1.77 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one K(3), one K(4), two equivalent K(1), one Co(1), and one Co(2) atom to form a mixture of distorted edge and corner-sharing OK4Co2 octahedra. The corner-sharing octahedral tilt angles are 63°. In the second O site, O(2) is bonded to one K(3), one K(4), two equivalent K(2), one Co(1), and one Co(2) atom to form a mixture of distorted edge and corner-sharing OK4Co2 octahedra. The corner-sharing octahedral tilt angles are 63°. In the third O site, O(3) is bonded in a 6-coordinate geometry to one K(1), one K(2), one K(3), two equivalent K(4), and one Co(2) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one K(1), one K(2), one K(4), two equivalent K(3), and one Co(1) atom.