Hg3Se2I2 crystallizes in the monoclinic C2/m space group. The structure consists of two hydriodic acid atoms inside a Hg12Se8I7 framework. In the Hg12Se8I7 framework, there are four inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a distorted see-saw-like geometry to one Se(1), one Se(2), one I(1), and one I(2) atom. In the second Hg site, Hg(2) is bonded in a distorted see-saw-like geometry to two equivalent Se(2), one I(1), and one I(3) atom. In the third Hg site, Hg(3) is bonded in a 2-coordinate geometry to one Se(1), one Se(2), one I(3), and one I(4) atom. In the fourth Hg site, Hg(4) is bonded in a distorted see-saw-like geometry to two equivalent Se(1), one I(2), and one I(3) atom. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one Hg(1), one Hg(3), and one Hg(4) atom. In the second Se site, Se(2) is bonded in a distorted T-shaped geometry to one Hg(1), one Hg(2), and one Hg(3) atom. There are four inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Hg(2) and two equivalent Hg(1) atoms. In the second I site, I(2) is bonded in a trigonal non-coplanar geometry to one Hg(4) and two equivalent Hg(1) atoms. In the third I site, I(3) is bonded in a distorted tetrahedral geometry to one Hg(2), one Hg(4), and two equivalent Hg(3) atoms. In the fourth I site, I(4) is bonded in a square co-planar geometry to four equivalent Hg(3) atoms.
Hg3Se2I2 crystallizes in the monoclinic C2/m space group. The structure consists of two hydriodic acid atoms inside a Hg12Se8I7 framework. In the Hg12Se8I7 framework, there are four inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a distorted see-saw-like geometry to one Se(1), one Se(2), one I(1), and one I(2) atom. The Hg(1)-Se(1) bond length is 2.55 Å. The Hg(1)-Se(2) bond length is 2.56 Å. The Hg(1)-I(1) bond length is 3.18 Å. The Hg(1)-I(2) bond length is 3.09 Å. In the second Hg site, Hg(2) is bonded in a distorted see-saw-like geometry to two equivalent Se(2), one I(1), and one I(3) atom. Both Hg(2)-Se(2) bond lengths are 2.53 Å. The Hg(2)-I(1) bond length is 3.17 Å. The Hg(2)-I(3) bond length is 3.33 Å. In the third Hg site, Hg(3) is bonded in a 2-coordinate geometry to one Se(1), one Se(2), one I(3), and one I(4) atom. The Hg(3)-Se(1) bond length is 2.52 Å. The Hg(3)-Se(2) bond length is 2.52 Å. The Hg(3)-I(3) bond length is 3.38 Å. The Hg(3)-I(4) bond length is 3.29 Å. In the fourth Hg site, Hg(4) is bonded in a distorted see-saw-like geometry to two equivalent Se(1), one I(2), and one I(3) atom. Both Hg(4)-Se(1) bond lengths are 2.53 Å. The Hg(4)-I(2) bond length is 3.12 Å. The Hg(4)-I(3) bond length is 3.34 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one Hg(1), one Hg(3), and one Hg(4) atom. In the second Se site, Se(2) is bonded in a distorted T-shaped geometry to one Hg(1), one Hg(2), and one Hg(3) atom. There are four inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Hg(2) and two equivalent Hg(1) atoms. In the second I site, I(2) is bonded in a trigonal non-coplanar geometry to one Hg(4) and two equivalent Hg(1) atoms. In the third I site, I(3) is bonded in a distorted tetrahedral geometry to one Hg(2), one Hg(4), and two equivalent Hg(3) atoms. In the fourth I site, I(4) is bonded in a square co-planar geometry to four equivalent Hg(3) atoms.