Rb3(SeO4)2 crystallizes in the trigonal R-3m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. In the second Rb site, Rb(2) is bonded in a 10-coordinate geometry to one O(2) and nine equivalent O(1) atoms. Se(1) is bonded in a tetrahedral geometry to one O(2) and three equivalent O(1) atoms. There are two inequivalent O sites. In the first 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 second O site, O(2) is bonded in a distorted single-bond geometry to one Rb(2) and one Se(1) atom.
Rb3(SeO4)2 crystallizes in the trigonal R-3m space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to six equivalent O(1) atoms. All Rb(1)-O(1) bond lengths are 3.01 Å. In the second Rb site, Rb(2) is bonded in a 10-coordinate geometry to one O(2) and nine equivalent O(1) atoms. The Rb(2)-O(2) bond length is 3.04 Å. There are three shorter (3.11 Å) and six longer (3.18 Å) Rb(2)-O(1) bond lengths. Se(1) is bonded in a tetrahedral geometry to one O(2) and three equivalent O(1) atoms. The Se(1)-O(2) bond length is 1.68 Å. All Se(1)-O(1) bond lengths are 1.68 Å. There are two inequivalent O sites. In the first 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 second O site, O(2) is bonded in a distorted single-bond geometry to one Rb(2) and one Se(1) atom.