Rb2CoO3 crystallizes in the monoclinic Cm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted trigonal bipyramidal geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(1), and two equivalent O(2) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to two equivalent Rb(1), two equivalent Rb(2), one Co(1), and one Co(2) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Co(1), and one Co(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Rb(2), four equivalent Rb(1), and one Co(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Rb(1), four equivalent Rb(2), and one Co(2) atom.
Rb2CoO3 crystallizes in the monoclinic Cm space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 7-coordinate geometry to one O(4), two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. The Rb(1)-O(4) bond length is 3.01 Å. There is one shorter (2.90 Å) and one longer (2.92 Å) Rb(1)-O(1) bond length. There is one shorter (2.89 Å) and one longer (2.96 Å) Rb(1)-O(2) bond length. There is one shorter (3.13 Å) and one longer (3.26 Å) Rb(1)-O(3) bond length. In the second Rb site, Rb(2) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. The Rb(2)-O(3) bond length is 3.02 Å. There is one shorter (2.90 Å) and one longer (2.92 Å) Rb(2)-O(1) bond length. There is one shorter (2.86 Å) and one longer (2.94 Å) Rb(2)-O(2) bond length. There is one shorter (3.14 Å) and one longer (3.27 Å) Rb(2)-O(4) bond length. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded in a distorted trigonal bipyramidal geometry to one O(3), two equivalent O(1), and two equivalent O(2) atoms. The Co(1)-O(3) bond length is 1.80 Å. Both Co(1)-O(1) bond lengths are 1.90 Å. Both Co(1)-O(2) bond lengths are 1.90 Å. In the second Co site, Co(2) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(1), and two equivalent O(2) atoms. The Co(2)-O(4) bond length is 1.78 Å. Both Co(2)-O(1) bond lengths are 1.95 Å. Both Co(2)-O(2) bond lengths are 1.95 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted water-like geometry to two equivalent Rb(1), two equivalent Rb(2), one Co(1), and one Co(2) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Co(1), and one Co(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Rb(2), four equivalent Rb(1), and one Co(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Rb(1), four equivalent Rb(2), and one Co(2) atom.