Cu2SiS3 is Enargite-like structured and crystallizes in the trigonal P31m space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(3), and two equivalent S(2) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with four equivalent Si(1)S4 tetrahedra, and corners with six equivalent Cu(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(3) and three equivalent S(1) atoms to form CuS4 tetrahedra that share corners with six equivalent Cu(1)S4 tetrahedra and corners with six equivalent Si(1)S4 tetrahedra. Si(1) is bonded to one S(2) and three equivalent S(1) atoms to form SiS4 tetrahedra that share corners with three equivalent Cu(2)S4 tetrahedra, corners with three equivalent Si(1)S4 tetrahedra, and corners with six equivalent Cu(1)S4 tetrahedra. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Cu(1), one Cu(2), and two equivalent Si(1) atoms to form SCu2Si2 tetrahedra that share corners with two equivalent S(3)Cu4 tetrahedra, corners with four equivalent S(2)Cu3Si tetrahedra, and corners with six equivalent S(1)Cu2Si2 tetrahedra. In the second S site, S(2) is bonded to three equivalent Cu(1) and one Si(1) atom to form SCu3Si tetrahedra that share corners with three equivalent S(2)Cu3Si tetrahedra, corners with three equivalent S(3)Cu4 tetrahedra, and corners with six equivalent S(1)Cu2Si2 tetrahedra. In the third S site, S(3) is bonded to one Cu(2) and three equivalent Cu(1) atoms to form SCu4 tetrahedra that share corners with six equivalent S(1)Cu2Si2 tetrahedra and corners with six equivalent S(2)Cu3Si tetrahedra.
Cu2SiS3 is Enargite-like structured and crystallizes in the trigonal P31m space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one S(1), one S(3), and two equivalent S(2) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with four equivalent Si(1)S4 tetrahedra, and corners with six equivalent Cu(1)S4 tetrahedra. The Cu(1)-S(1) bond length is 2.29 Å. The Cu(1)-S(3) bond length is 2.22 Å. Both Cu(1)-S(2) bond lengths are 2.29 Å. In the second Cu site, Cu(2) is bonded to one S(3) and three equivalent S(1) atoms to form CuS4 tetrahedra that share corners with six equivalent Cu(1)S4 tetrahedra and corners with six equivalent Si(1)S4 tetrahedra. The Cu(2)-S(3) bond length is 2.24 Å. All Cu(2)-S(1) bond lengths are 2.43 Å. Si(1) is bonded to one S(2) and three equivalent S(1) atoms to form SiS4 tetrahedra that share corners with three equivalent Cu(2)S4 tetrahedra, corners with three equivalent Si(1)S4 tetrahedra, and corners with six equivalent Cu(1)S4 tetrahedra. The Si(1)-S(2) bond length is 2.07 Å. All Si(1)-S(1) bond lengths are 2.27 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Cu(1), one Cu(2), and two equivalent Si(1) atoms to form SCu2Si2 tetrahedra that share corners with two equivalent S(3)Cu4 tetrahedra, corners with four equivalent S(2)Cu3Si tetrahedra, and corners with six equivalent S(1)Cu2Si2 tetrahedra. In the second S site, S(2) is bonded to three equivalent Cu(1) and one Si(1) atom to form SCu3Si tetrahedra that share corners with three equivalent S(2)Cu3Si tetrahedra, corners with three equivalent S(3)Cu4 tetrahedra, and corners with six equivalent S(1)Cu2Si2 tetrahedra. In the third S site, S(3) is bonded to one Cu(2) and three equivalent Cu(1) atoms to form SCu4 tetrahedra that share corners with six equivalent S(1)Cu2Si2 tetrahedra and corners with six equivalent S(2)Cu3Si tetrahedra.