Hg3Se2I2 crystallizes in the monoclinic C2/m space group. There are three 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 rectangular see-saw-like geometry to one Se(1), one Se(2), one I(3), and one I(4) atom. In the third Hg site, Hg(3,4) is bonded in a distorted see-saw-like geometry to two equivalent Se(1), one I(1), and one I(4) 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(2); and one Hg(3,4) 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(3,4) 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(3,4) and two equivalent Hg(1) atoms. In the second I site, I(2) is bonded in a trigonal non-coplanar geometry to one Hg(3,4) and two equivalent Hg(1) atoms. In the third I site, I(3) is bonded in an L-shaped geometry to two equivalent Hg(2) atoms. In the fourth I site, I(4) is bonded in a tetrahedral geometry to two equivalent Hg(2) and two equivalent Hg(3,4) atoms.
Hg3Se2I2 crystallizes in the monoclinic C2/m space group. There are three 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 2.57 Å. The Hg(1)-Se(2) bond length is 2.56 Å. The Hg(1)-I(1) bond length is 3.16 Å. The Hg(1)-I(2) bond length is 3.16 Å. In the second Hg site, Hg(2) is bonded in a distorted rectangular see-saw-like geometry to one Se(1), one Se(2), one I(3), and one I(4) atom. The Hg(2)-Se(1) bond length is 2.54 Å. The Hg(2)-Se(2) bond length is 2.54 Å. The Hg(2)-I(3) bond length is 3.23 Å. The Hg(2)-I(4) bond length is 3.32 Å. In the third Hg site, Hg(3,4) is bonded in a distorted see-saw-like geometry to two equivalent Se(1), one I(1), and one I(4) atom. Both Hg(3,4)-Se(1) bond lengths are 2.55 Å. The Hg(3,4)-I(1) bond length is 3.12 Å. The Hg(3,4)-I(4) bond length is 3.33 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(2); and one Hg(3,4) 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(3,4) atom. The Se(2)-Hg(3,4) bond length is 2.55 Å. There are four inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Hg(3,4) and two equivalent Hg(1) atoms. In the second I site, I(2) is bonded in a trigonal non-coplanar geometry to one Hg(3,4) and two equivalent Hg(1) atoms. The I(2)-Hg(3,4) bond length is 3.12 Å. In the third I site, I(3) is bonded in an L-shaped geometry to two equivalent Hg(2) atoms. In the fourth I site, I(4) is bonded in a tetrahedral geometry to two equivalent Hg(2) and two equivalent Hg(3,4) atoms.