Rb3(SeO4)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(3), three equivalent O(1), and three equivalent O(2) atoms. Se(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Rb(2), two equivalent Rb(1), and one Se(1) atom. In the second O site, O(1) is bonded in a distorted single-bond geometry to one Rb(1), three equivalent Rb(2), and one Se(1) atom. In the third O site, O(2) is bonded in a distorted single-bond geometry to one Rb(1), three equivalent Rb(2), and one Se(1) atom. In the fourth O site, O(3) is bonded in a 1-coordinate geometry to one Rb(1), two equivalent Rb(2), and one Se(1) atom.
Rb3(SeO4)2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and four equivalent O(4) atoms. Both Rb(1)-O(1) bond lengths are 3.08 Å. Both Rb(1)-O(2) bond lengths are 3.06 Å. Both Rb(1)-O(3) bond lengths are 2.93 Å. There are two shorter (3.34 Å) and two longer (3.36 Å) Rb(1)-O(4) bond lengths. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one O(4), two equivalent O(3), three equivalent O(1), and three equivalent O(2) atoms. The Rb(2)-O(4) bond length is 3.17 Å. There is one shorter (3.13 Å) and one longer (3.23 Å) Rb(2)-O(3) bond length. There are a spread of Rb(2)-O(1) bond distances ranging from 3.02-3.16 Å. There are a spread of Rb(2)-O(2) bond distances ranging from 2.95-3.25 Å. Se(1) is bonded in a tetrahedral geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Se(1)-O(1) bond length is 1.66 Å. The Se(1)-O(2) bond length is 1.66 Å. The Se(1)-O(3) bond length is 1.68 Å. The Se(1)-O(4) bond length is 1.71 Å. There are four inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Rb(2), two equivalent Rb(1), and one Se(1) atom. In the second O site, O(1) is bonded in a distorted single-bond geometry to one Rb(1), three equivalent Rb(2), and one Se(1) atom. In the third O site, O(2) is bonded in a distorted single-bond geometry to one Rb(1), three equivalent Rb(2), and one Se(1) atom. In the fourth O site, O(3) is bonded in a 1-coordinate geometry to one Rb(1), two equivalent Rb(2), and one Se(1) atom.