Rb6HgS4 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to one S(1) and three equivalent S(2) atoms to form distorted RbS4 tetrahedra that share corners with two equivalent Hg(1)S4 tetrahedra, corners with eight equivalent Rb(1)S4 tetrahedra, and  an edgeedge with one Hg(1)S4 tetrahedra. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one S(1) and four equivalent S(2) atoms. Hg(1) is bonded to one S(1) and three equivalent S(2) atoms to form distorted HgS4 tetrahedra that share corners with six equivalent Rb(1)S4 tetrahedra and edges with three equivalent Rb(1)S4 tetrahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to three equivalent Rb(1), three equivalent Rb(2), and one Hg(1) atom. In the second S site, S(2) is bonded in a 8-coordinate geometry to three equivalent Rb(1), four equivalent Rb(2), and one Hg(1) atom.
Rb6HgS4 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded to one S(1) and three equivalent S(2) atoms to form distorted RbS4 tetrahedra that share corners with two equivalent Hg(1)S4 tetrahedra, corners with eight equivalent Rb(1)S4 tetrahedra, and  an edgeedge with one Hg(1)S4 tetrahedra. The Rb(1)-S(1) bond length is 3.34 Å. There is one shorter (3.26 Å) and two longer (3.28 Å) Rb(1)-S(2) bond lengths. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one S(1) and four equivalent S(2) atoms. The Rb(2)-S(1) bond length is 3.41 Å. There are two shorter (3.36 Å) and two longer (3.61 Å) Rb(2)-S(2) bond lengths. Hg(1) is bonded to one S(1) and three equivalent S(2) atoms to form distorted HgS4 tetrahedra that share corners with six equivalent Rb(1)S4 tetrahedra and edges with three equivalent Rb(1)S4 tetrahedra. The Hg(1)-S(1) bond length is 2.66 Å. All Hg(1)-S(2) bond lengths are 2.64 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to three equivalent Rb(1), three equivalent Rb(2), and one Hg(1) atom. In the second S site, S(2) is bonded in a 8-coordinate geometry to three equivalent Rb(1), four equivalent Rb(2), and one Hg(1) atom.