Rb2Se2O7 crystallizes in the monoclinic C2/c space group. Rb(1) is bonded in a 8-coordinate geometry to two equivalent O(3), three equivalent O(1), and three equivalent O(2) atoms. Se(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SeO4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to three equivalent Rb(1) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Se(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent Se(1) atoms.
Rb2Se2O7 crystallizes in the monoclinic C2/c space group. Rb(1) is bonded in a 8-coordinate geometry to two equivalent O(3), three equivalent O(1), and three equivalent O(2) atoms. There is one shorter (2.96 Å) and one longer (3.07 Å) Rb(1)-O(3) bond length. There are a spread of Rb(1)-O(1) bond distances ranging from 2.92-3.26 Å. There are a spread of Rb(1)-O(2) bond distances ranging from 2.86-2.95 Å. Se(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form corner-sharing SeO4 tetrahedra. The Se(1)-O(1) bond length is 1.63 Å. The Se(1)-O(2) bond length is 1.63 Å. The Se(1)-O(3) bond length is 1.62 Å. The Se(1)-O(4) bond length is 1.81 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 1-coordinate geometry to three equivalent Rb(1) and one Se(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one Se(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Rb(1) and one Se(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to two equivalent Se(1) atoms.