Rb2SeO4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to two equivalent O(2), three equivalent O(3), and four equivalent O(1) atoms. In the second Rb site, Rb(2) is bonded in a 10-coordinate geometry to one O(3), three equivalent O(2), and six equivalent O(1) atoms. Se(1) is bonded in a tetrahedral geometry to one O(2), one O(3), and two equivalent O(1) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent 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 two equivalent Rb(1), three equivalent Rb(2), and one Se(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Rb(2), three equivalent Rb(1), and one Se(1) atom.
Rb2SeO4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to two equivalent O(2), three equivalent O(3), and four equivalent O(1) atoms. There is one shorter (2.91 Å) and one longer (2.93 Å) Rb(1)-O(2) bond length. There is one shorter (3.08 Å) and two longer (3.35 Å) Rb(1)-O(3) bond lengths. There are two shorter (2.86 Å) and two longer (2.94 Å) Rb(1)-O(1) bond lengths. In the second Rb site, Rb(2) is bonded in a 10-coordinate geometry to one O(3), three equivalent O(2), and six equivalent O(1) atoms. The Rb(2)-O(3) bond length is 2.82 Å. There are two shorter (3.10 Å) and one longer (3.33 Å) Rb(2)-O(2) bond length. There are a spread of Rb(2)-O(1) bond distances ranging from 3.12-3.31 Å. Se(1) is bonded in a tetrahedral geometry to one O(2), one O(3), and two equivalent O(1) atoms. The Se(1)-O(2) bond length is 1.66 Å. The Se(1)-O(3) bond length is 1.65 Å. Both Se(1)-O(1) bond lengths are 1.66 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent 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 two equivalent Rb(1), three equivalent Rb(2), and one Se(1) atom. In the third O site, O(3) is bonded in a 1-coordinate geometry to one Rb(2), three equivalent Rb(1), and one Se(1) atom.