HgSeO4 crystallizes in the orthorhombic Pmn2_1 space group. Hg(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. Se(1) is bonded in a tetrahedral geometry to one O(1), one O(2), and two equivalent O(3) atoms. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Hg(1) and one Se(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Hg(1) and one Se(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Hg(1) and one Se(1) atom.
HgSeO4 crystallizes in the orthorhombic Pmn2_1 space group. Hg(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(3) atoms. The Hg(1)-O(1) bond length is 2.42 Å. The Hg(1)-O(2) bond length is 2.31 Å. Both Hg(1)-O(3) bond lengths are 2.27 Å. Se(1) is bonded in a tetrahedral geometry to one O(1), one O(2), and two equivalent O(3) atoms. The Se(1)-O(1) bond length is 1.65 Å. The Se(1)-O(2) bond length is 1.65 Å. Both Se(1)-O(3) bond lengths are 1.67 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Hg(1) and one Se(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Hg(1) and one Se(1) atom. In the third O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Hg(1) and one Se(1) atom.