Hg4SiS6 crystallizes in the monoclinic Cc space group. There are four inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to one S(1), one S(2), one S(5), and one S(6) atom to form HgS4 trigonal pyramids that share corners with two equivalent Hg(4)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Hg(2)S4 tetrahedra, and corners with three equivalent Hg(3)S4 tetrahedra. In the second Hg site, Hg(2) is bonded to one S(1), one S(2), one S(4), and one S(5) atom to form HgS4 tetrahedra that share corners with two equivalent Hg(3)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Hg(4)S4 tetrahedra, and corners with three equivalent Hg(1)S4 trigonal pyramids. In the third Hg site, Hg(3) is bonded to one S(1), one S(3), one S(5), and one S(6) atom to form HgS4 tetrahedra that share corners with two equivalent Hg(2)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Hg(4)S4 tetrahedra, and corners with three equivalent Hg(1)S4 trigonal pyramids. In the fourth Hg site, Hg(4) is bonded to one S(1), one S(3), one S(4), and one S(5) atom to form HgS4 tetrahedra that share corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Hg(2)S4 tetrahedra, corners with three equivalent Hg(3)S4 tetrahedra, and corners with two equivalent Hg(1)S4 trigonal pyramids. Si(1) is bonded to one S(2), one S(3), one S(4), and one S(6) atom to form SiS4 tetrahedra that share corners with two equivalent Hg(2)S4 tetrahedra, corners with two equivalent Hg(3)S4 tetrahedra, corners with two equivalent Hg(4)S4 tetrahedra, and corners with two equivalent Hg(1)S4 trigonal pyramids. There are six inequivalent S sites. In the first S site, S(1) is bonded to one Hg(1), one Hg(2), one Hg(3), and one Hg(4) atom to form corner-sharing SHg4 tetrahedra. In the second S site, S(2) is bonded in a trigonal non-coplanar geometry to one Hg(1), one Hg(2), and one Si(1) atom. In the third S site, S(3) is bonded in a trigonal non-coplanar geometry to one Hg(3), one Hg(4), and one Si(1) atom. In the fourth S site, S(4) is bonded in a trigonal non-coplanar geometry to one Hg(2), one Hg(4), and one Si(1) atom. In the fifth S site, S(5) is bonded to one Hg(1), one Hg(2), one Hg(3), and one Hg(4) atom to form corner-sharing SHg4 tetrahedra. In the sixth S site, S(6) is bonded in a distorted trigonal non-coplanar geometry to one Hg(1), one Hg(3), and one Si(1) atom.
Hg4SiS6 crystallizes in the monoclinic Cc space group. There are four inequivalent Hg sites. In the first Hg site, Hg(1) is bonded to one S(1), one S(2), one S(5), and one S(6) atom to form HgS4 trigonal pyramids that share corners with two equivalent Hg(4)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Hg(2)S4 tetrahedra, and corners with three equivalent Hg(3)S4 tetrahedra. The Hg(1)-S(1) bond length is 2.63 Å. The Hg(1)-S(2) bond length is 2.80 Å. The Hg(1)-S(5) bond length is 2.58 Å. The Hg(1)-S(6) bond length is 2.60 Å. In the second Hg site, Hg(2) is bonded to one S(1), one S(2), one S(4), and one S(5) atom to form HgS4 tetrahedra that share corners with two equivalent Hg(3)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Hg(4)S4 tetrahedra, and corners with three equivalent Hg(1)S4 trigonal pyramids. The Hg(2)-S(1) bond length is 2.57 Å. The Hg(2)-S(2) bond length is 2.60 Å. The Hg(2)-S(4) bond length is 2.60 Å. The Hg(2)-S(5) bond length is 2.68 Å. In the third Hg site, Hg(3) is bonded to one S(1), one S(3), one S(5), and one S(6) atom to form HgS4 tetrahedra that share corners with two equivalent Hg(2)S4 tetrahedra, corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Hg(4)S4 tetrahedra, and corners with three equivalent Hg(1)S4 trigonal pyramids. The Hg(3)-S(1) bond length is 2.56 Å. The Hg(3)-S(3) bond length is 2.74 Å. The Hg(3)-S(5) bond length is 2.58 Å. The Hg(3)-S(6) bond length is 2.61 Å. In the fourth Hg site, Hg(4) is bonded to one S(1), one S(3), one S(4), and one S(5) atom to form HgS4 tetrahedra that share corners with two equivalent Si(1)S4 tetrahedra, corners with three equivalent Hg(2)S4 tetrahedra, corners with three equivalent Hg(3)S4 tetrahedra, and corners with two equivalent Hg(1)S4 trigonal pyramids. The Hg(4)-S(1) bond length is 2.66 Å. The Hg(4)-S(3) bond length is 2.63 Å. The Hg(4)-S(4) bond length is 2.70 Å. The Hg(4)-S(5) bond length is 2.56 Å. Si(1) is bonded to one S(2), one S(3), one S(4), and one S(6) atom to form SiS4 tetrahedra that share corners with two equivalent Hg(2)S4 tetrahedra, corners with two equivalent Hg(3)S4 tetrahedra, corners with two equivalent Hg(4)S4 tetrahedra, and corners with two equivalent Hg(1)S4 trigonal pyramids. The Si(1)-S(2) bond length is 2.12 Å. The Si(1)-S(3) bond length is 2.13 Å. The Si(1)-S(4) bond length is 2.15 Å. The Si(1)-S(6) bond length is 2.16 Å. There are six inequivalent S sites. In the first S site, S(1) is bonded to one Hg(1), one Hg(2), one Hg(3), and one Hg(4) atom to form corner-sharing SHg4 tetrahedra. In the second S site, S(2) is bonded in a trigonal non-coplanar geometry to one Hg(1), one Hg(2), and one Si(1) atom. In the third S site, S(3) is bonded in a trigonal non-coplanar geometry to one Hg(3), one Hg(4), and one Si(1) atom. In the fourth S site, S(4) is bonded in a trigonal non-coplanar geometry to one Hg(2), one Hg(4), and one Si(1) atom. In the fifth S site, S(5) is bonded to one Hg(1), one Hg(2), one Hg(3), and one Hg(4) atom to form corner-sharing SHg4 tetrahedra. In the sixth S site, S(6) is bonded in a distorted trigonal non-coplanar geometry to one Hg(1), one Hg(3), and one Si(1) atom.