Rb8C4O7 crystallizes in the monoclinic Pm space group. There are five inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a distorted T-shaped geometry to one C(3) and two equivalent O(1) atoms. In the second Rb site, Rb(2) is bonded in a 2-coordinate geometry to two equivalent O(3) atoms. In the third Rb site, Rb(3) is bonded in a distorted L-shaped geometry to one C(3), one O(1), and one O(4) atom. In the fourth Rb site, Rb(4) is bonded in a 6-coordinate geometry to one C(1), one C(2), one O(1), one O(2), one O(3), and one O(4) atom. In the fifth Rb site, Rb(5) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(4) atoms. There are three inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one Rb(4), one O(1), and one O(4) atom. In the second C site, C(2) is bonded in a single-bond geometry to two equivalent Rb(4) and one O(2) atom. In the third C site, C(3) is bonded in a 3-coordinate geometry to one Rb(1) and two equivalent Rb(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(3), one Rb(4), one Rb(5), and one C(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to two equivalent Rb(4) and one C(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Rb(2), one Rb(4), and one Rb(5) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Rb(3), one Rb(4), two equivalent Rb(5), and one C(1) atom.
Rb8C4O7 crystallizes in the monoclinic Pm space group. There are five inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a distorted T-shaped geometry to one C(3) and two equivalent O(1) atoms. The Rb(1)-C(3) bond length is 3.11 Å. Both Rb(1)-O(1) bond lengths are 3.17 Å. In the second Rb site, Rb(2) is bonded in a 2-coordinate geometry to two equivalent O(3) atoms. Both Rb(2)-O(3) bond lengths are 2.66 Å. In the third Rb site, Rb(3) is bonded in a distorted L-shaped geometry to one C(3), one O(1), and one O(4) atom. The Rb(3)-C(3) bond length is 3.45 Å. The Rb(3)-O(1) bond length is 2.81 Å. The Rb(3)-O(4) bond length is 2.71 Å. In the fourth Rb site, Rb(4) is bonded in a 6-coordinate geometry to one C(1), one C(2), one O(1), one O(2), one O(3), and one O(4) atom. The Rb(4)-C(1) bond length is 3.42 Å. The Rb(4)-C(2) bond length is 3.35 Å. The Rb(4)-O(1) bond length is 3.37 Å. The Rb(4)-O(2) bond length is 3.23 Å. The Rb(4)-O(3) bond length is 2.51 Å. The Rb(4)-O(4) bond length is 2.94 Å. In the fifth Rb site, Rb(5) is bonded in a 4-coordinate geometry to one O(1), one O(3), and two equivalent O(4) atoms. The Rb(5)-O(1) bond length is 3.10 Å. The Rb(5)-O(3) bond length is 2.58 Å. There is one shorter (3.00 Å) and one longer (3.08 Å) Rb(5)-O(4) bond length. There are three inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one Rb(4), one O(1), and one O(4) atom. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(4) bond length is 1.28 Å. In the second C site, C(2) is bonded in a single-bond geometry to two equivalent Rb(4) and one O(2) atom. The C(2)-O(2) bond length is 1.16 Å. In the third C site, C(3) is bonded in a 3-coordinate geometry to one Rb(1) and two equivalent Rb(3) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(3), one Rb(4), one Rb(5), and one C(1) atom. In the second O site, O(2) is bonded in a single-bond geometry to two equivalent Rb(4) and one C(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Rb(2), one Rb(4), and one Rb(5) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Rb(3), one Rb(4), two equivalent Rb(5), and one C(1) atom.