(Hg2SeO4)12O2 crystallizes in the trigonal R-3 space group. The structure consists of three water atoms inside a Hg2SeO4 framework. In the Hg2SeO4 framework, there are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a distorted linear geometry to one O(1) and two equivalent O(4) atoms. In the second Hg site, Hg(2) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 2-coordinate geometry to one Hg(2) and one Se(1) atom. In the second O site, O(4) is bonded to two equivalent Hg(1) and two equivalent Hg(2) atoms to form corner-sharing OHg4 tetrahedra. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Hg(1), two equivalent Hg(2), and one Se(1) atom. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Hg(2) and one Se(1) atom.
(Hg2SeO4)12O2 crystallizes in the trigonal R-3 space group. The structure consists of three water atoms inside a Hg2SeO4 framework. In the Hg2SeO4 framework, there are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a distorted linear geometry to one O(1) and two equivalent O(4) atoms. The Hg(1)-O(1) bond length is 2.69 Å. There is one shorter (2.11 Å) and one longer (2.12 Å) Hg(1)-O(4) bond length. In the second Hg site, Hg(2) is bonded in a 7-coordinate geometry to one O(3), two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms. The Hg(2)-O(3) bond length is 2.54 Å. There is one shorter (2.31 Å) and one longer (2.59 Å) Hg(2)-O(1) bond length. There is one shorter (2.63 Å) and one longer (2.65 Å) Hg(2)-O(2) bond length. There is one shorter (2.29 Å) and one longer (2.53 Å) Hg(2)-O(4) bond length. Se(1) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(3) atom. The Se(1)-O(1) bond length is 1.77 Å. The Se(1)-O(2) bond length is 1.72 Å. The Se(1)-O(3) bond length is 1.71 Å. There are four inequivalent O sites. In the first O site, O(3) is bonded in a 2-coordinate geometry to one Hg(2) and one Se(1) atom. In the second O site, O(4) is bonded to two equivalent Hg(1) and two equivalent Hg(2) atoms to form corner-sharing OHg4 tetrahedra. In the third O site, O(1) is bonded in a 4-coordinate geometry to one Hg(1), two equivalent Hg(2), and one Se(1) atom. In the fourth O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Hg(2) and one Se(1) atom.