Rb3H(SeO4)2 crystallizes in the monoclinic Cc space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one O(2), one O(4), one O(8), two equivalent O(1), two equivalent O(5), and two equivalent O(7) atoms. In the third Rb site, Rb(3) is bonded in a 10-coordinate geometry to one O(1), one O(3), one O(5), one O(7), two equivalent O(2), two equivalent O(6), and two equivalent O(8) atoms. H(1) is bonded in a linear geometry to one O(3) and one O(4) atom. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a tetrahedral geometry to one O(1), one O(3), one O(5), and one O(7) atom. In the second Se site, Se(2) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(6), and one O(8) atom. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(3), two equivalent Rb(2), and one Se(1) atom. In the second O site, O(6) is bonded in a 1-coordinate geometry to one Rb(1), two equivalent Rb(3), and one Se(2) atom. In the third O site, O(7) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(3), two equivalent Rb(2), and one Se(1) atom. In the fourth O site, O(8) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one Se(2) atom. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(3), two equivalent Rb(2), and one Se(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one Se(2) atom. In the seventh O site, O(3) is bonded in a distorted water-like geometry to one Rb(3), one H(1), and one Se(1) atom. In the eighth O site, O(4) is bonded in a 2-coordinate geometry to one Rb(2), one H(1), and one Se(2) atom.
Rb3H(SeO4)2 crystallizes in the monoclinic Cc space group. There are three inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), one O(6), one O(7), and one O(8) atom. The Rb(1)-O(1) bond length is 3.11 Å. The Rb(1)-O(2) bond length is 3.12 Å. The Rb(1)-O(5) bond length is 2.91 Å. The Rb(1)-O(6) bond length is 2.92 Å. The Rb(1)-O(7) bond length is 3.06 Å. The Rb(1)-O(8) bond length is 3.08 Å. In the second Rb site, Rb(2) is bonded in a 9-coordinate geometry to one O(2), one O(4), one O(8), two equivalent O(1), two equivalent O(5), and two equivalent O(7) atoms. The Rb(2)-O(2) bond length is 2.99 Å. The Rb(2)-O(4) bond length is 3.15 Å. The Rb(2)-O(8) bond length is 3.04 Å. There is one shorter (3.18 Å) and one longer (3.24 Å) Rb(2)-O(1) bond length. There is one shorter (3.17 Å) and one longer (3.28 Å) Rb(2)-O(5) bond length. There is one shorter (3.11 Å) and one longer (3.23 Å) Rb(2)-O(7) bond length. In the third Rb site, Rb(3) is bonded in a 10-coordinate geometry to one O(1), one O(3), one O(5), one O(7), two equivalent O(2), two equivalent O(6), and two equivalent O(8) atoms. The Rb(3)-O(1) bond length is 2.97 Å. The Rb(3)-O(3) bond length is 3.20 Å. The Rb(3)-O(5) bond length is 3.53 Å. The Rb(3)-O(7) bond length is 3.02 Å. There is one shorter (3.17 Å) and one longer (3.25 Å) Rb(3)-O(2) bond length. There is one shorter (3.19 Å) and one longer (3.30 Å) Rb(3)-O(6) bond length. There is one shorter (3.13 Å) and one longer (3.23 Å) Rb(3)-O(8) bond length. H(1) is bonded in a linear geometry to one O(3) and one O(4) atom. The H(1)-O(3) bond length is 1.41 Å. The H(1)-O(4) bond length is 1.09 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a tetrahedral geometry to one O(1), one O(3), one O(5), and one O(7) atom. The Se(1)-O(1) bond length is 1.67 Å. The Se(1)-O(3) bond length is 1.72 Å. The Se(1)-O(5) bond length is 1.67 Å. The Se(1)-O(7) bond length is 1.67 Å. In the second Se site, Se(2) is bonded in a tetrahedral geometry to one O(2), one O(4), one O(6), and one O(8) atom. The Se(2)-O(2) bond length is 1.66 Å. The Se(2)-O(4) bond length is 1.76 Å. The Se(2)-O(6) bond length is 1.65 Å. The Se(2)-O(8) bond length is 1.66 Å. There are eight inequivalent O sites. In the first O site, O(5) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(3), two equivalent Rb(2), and one Se(1) atom. In the second O site, O(6) is bonded in a 1-coordinate geometry to one Rb(1), two equivalent Rb(3), and one Se(2) atom. In the third O site, O(7) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(3), two equivalent Rb(2), and one Se(1) atom. In the fourth O site, O(8) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one Se(2) atom. In the fifth O site, O(1) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(3), two equivalent Rb(2), and one Se(1) atom. In the sixth O site, O(2) is bonded in a distorted single-bond geometry to one Rb(1), one Rb(2), two equivalent Rb(3), and one Se(2) atom. In the seventh O site, O(3) is bonded in a distorted water-like geometry to one Rb(3), one H(1), and one Se(1) atom. In the eighth O site, O(4) is bonded in a 2-coordinate geometry to one Rb(2), one H(1), and one Se(2) atom.