Rb4CO6 crystallizes in the triclinic P1 space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), one O(4), and one O(5) atom. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(6) atom. In the third Rb site, Rb(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and two equivalent O(3) atoms. In the fourth Rb site, Rb(4) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(6) atom. C(1) is bonded in a trigonal planar geometry to one O(1), one O(3), and one O(6) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Rb(2), one Rb(3), one Rb(4), and one C(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Rb(1), one Rb(2), one Rb(3), and one Rb(4) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal bipyramidal geometry to one Rb(1), one Rb(2), one Rb(3), one Rb(4), and one O(5) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(3), and one O(4) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(3), one Rb(4), and one C(1) atom.
Rb4CO6 crystallizes in the triclinic P1 space group. There are four inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 4-coordinate geometry to one O(2), one O(3), one O(4), and one O(5) atom. The Rb(1)-O(2) bond length is 2.71 Å. The Rb(1)-O(3) bond length is 2.76 Å. The Rb(1)-O(4) bond length is 2.88 Å. The Rb(1)-O(5) bond length is 3.28 Å. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(6) atom. The Rb(2)-O(1) bond length is 2.89 Å. The Rb(2)-O(2) bond length is 2.75 Å. The Rb(2)-O(3) bond length is 3.11 Å. The Rb(2)-O(4) bond length is 2.94 Å. The Rb(2)-O(6) bond length is 2.84 Å. In the third Rb site, Rb(3) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), and two equivalent O(3) atoms. The Rb(3)-O(1) bond length is 2.89 Å. The Rb(3)-O(2) bond length is 2.81 Å. The Rb(3)-O(4) bond length is 3.33 Å. The Rb(3)-O(5) bond length is 3.42 Å. The Rb(3)-O(6) bond length is 2.76 Å. There is one shorter (2.84 Å) and one longer (3.07 Å) Rb(3)-O(3) bond length. In the fourth Rb site, Rb(4) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(4), and one O(6) atom. The Rb(4)-O(1) bond length is 2.87 Å. The Rb(4)-O(2) bond length is 2.65 Å. The Rb(4)-O(4) bond length is 2.97 Å. The Rb(4)-O(6) bond length is 3.08 Å. C(1) is bonded in a trigonal planar geometry to one O(1), one O(3), and one O(6) atom. The C(1)-O(1) bond length is 1.31 Å. The C(1)-O(3) bond length is 1.31 Å. The C(1)-O(6) bond length is 1.30 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Rb(2), one Rb(3), one Rb(4), and one C(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to one Rb(1), one Rb(2), one Rb(3), and one Rb(4) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal bipyramidal geometry to one Rb(1), one Rb(2), one Rb(3), one Rb(4), and one O(5) atom. The O(4)-O(5) bond length is 1.33 Å. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(3), and one O(4) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Rb(2), one Rb(3), one Rb(4), and one C(1) atom.