Cu8SiS6 crystallizes in the orthorhombic Pmn2_1 space group. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 3-coordinate geometry to one S(1), one S(2), and one S(3) atom. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one S(1), one S(5), and two equivalent S(4) atoms. In the third Cu site, Cu(3) is bonded in a 3-coordinate geometry to one S(3), one S(4), and one S(5) atom. In the fourth Cu site, Cu(4) is bonded in a 4-coordinate geometry to one S(1), one S(3), one S(4), and one S(5) atom. In the fifth Cu site, Cu(5) is bonded in a 3-coordinate geometry to one S(1), one S(2), and one S(4) atom. Si(1) is bonded in a tetrahedral geometry to one S(2), one S(3), and two equivalent S(4) atoms. There are five inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to one Cu(1), one Cu(2), two equivalent Cu(4), and two equivalent Cu(5) atoms. In the second S site, S(2) is bonded in a tetrahedral geometry to one Cu(1), two equivalent Cu(5), and one Si(1) atom. In the third S site, S(3) is bonded in a 6-coordinate geometry to one Cu(1), two equivalent Cu(3), two equivalent Cu(4), and one Si(1) atom. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to one Cu(2), one Cu(3), one Cu(4), one Cu(5), and one Si(1) atom. In the fifth S site, S(5) is bonded in a distorted trigonal bipyramidal geometry to one Cu(2), two equivalent Cu(3), and two equivalent Cu(4) atoms.
Cu8SiS6 crystallizes in the orthorhombic Pmn2_1 space group. There are five inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a 3-coordinate geometry to one S(1), one S(2), and one S(3) atom. The Cu(1)-S(1) bond length is 2.29 Å. The Cu(1)-S(2) bond length is 2.27 Å. The Cu(1)-S(3) bond length is 2.51 Å. In the second Cu site, Cu(2) is bonded in a 4-coordinate geometry to one S(1), one S(5), and two equivalent S(4) atoms. The Cu(2)-S(1) bond length is 2.41 Å. The Cu(2)-S(5) bond length is 2.32 Å. Both Cu(2)-S(4) bond lengths are 2.42 Å. In the third Cu site, Cu(3) is bonded in a 3-coordinate geometry to one S(3), one S(4), and one S(5) atom. The Cu(3)-S(3) bond length is 2.31 Å. The Cu(3)-S(4) bond length is 2.42 Å. The Cu(3)-S(5) bond length is 2.23 Å. In the fourth Cu site, Cu(4) is bonded in a 4-coordinate geometry to one S(1), one S(3), one S(4), and one S(5) atom. The Cu(4)-S(1) bond length is 2.41 Å. The Cu(4)-S(3) bond length is 2.59 Å. The Cu(4)-S(4) bond length is 2.50 Å. The Cu(4)-S(5) bond length is 2.31 Å. In the fifth Cu site, Cu(5) is bonded in a 3-coordinate geometry to one S(1), one S(2), and one S(4) atom. The Cu(5)-S(1) bond length is 2.30 Å. The Cu(5)-S(2) bond length is 2.37 Å. The Cu(5)-S(4) bond length is 2.34 Å. Si(1) is bonded in a tetrahedral geometry to one S(2), one S(3), and two equivalent S(4) atoms. The Si(1)-S(2) bond length is 2.11 Å. The Si(1)-S(3) bond length is 2.14 Å. Both Si(1)-S(4) bond lengths are 2.12 Å. There are five inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to one Cu(1), one Cu(2), two equivalent Cu(4), and two equivalent Cu(5) atoms. In the second S site, S(2) is bonded in a tetrahedral geometry to one Cu(1), two equivalent Cu(5), and one Si(1) atom. In the third S site, S(3) is bonded in a 6-coordinate geometry to one Cu(1), two equivalent Cu(3), two equivalent Cu(4), and one Si(1) atom. In the fourth S site, S(4) is bonded in a 5-coordinate geometry to one Cu(2), one Cu(3), one Cu(4), one Cu(5), and one Si(1) atom. In the fifth S site, S(5) is bonded in a distorted trigonal bipyramidal geometry to one Cu(2), two equivalent Cu(3), and two equivalent Cu(4) atoms.