Cu2GeS3 is Enargite-like structured and crystallizes in the monoclinic Cc 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(1)S4 tetrahedra, corners with five equivalent Cu(2)S4 tetrahedra, and corners with five equivalent Ge(1)S4 tetrahedra. In the second Cu site, Cu(2) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with five equivalent Cu(1)S4 tetrahedra, and corners with five equivalent Ge(1)S4 tetrahedra. Ge(1) is bonded to one S(1), one S(2), and two equivalent S(3) atoms to form GeS4 tetrahedra that share corners with two equivalent Ge(1)S4 tetrahedra, corners with five equivalent Cu(1)S4 tetrahedra, and corners with five equivalent Cu(2)S4 tetrahedra. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Cu(1), two equivalent Cu(2), and one Ge(1) atom to form SCu3Ge tetrahedra that share corners with two equivalent S(1)Cu3Ge tetrahedra, corners with five equivalent S(3)Cu2Ge2 tetrahedra, and corners with five equivalent S(2)Cu3Ge tetrahedra. In the second S site, S(2) is bonded to one Cu(2), two equivalent Cu(1), and one Ge(1) atom to form SCu3Ge tetrahedra that share corners with two equivalent S(2)Cu3Ge tetrahedra, corners with five equivalent S(3)Cu2Ge2 tetrahedra, and corners with five equivalent S(1)Cu3Ge tetrahedra. In the third S site, S(3) is bonded to one Cu(1), one Cu(2), and two equivalent Ge(1) atoms to form SCu2Ge2 tetrahedra that share corners with two equivalent S(3)Cu2Ge2 tetrahedra, corners with five equivalent S(1)Cu3Ge tetrahedra, and corners with five equivalent S(2)Cu3Ge tetrahedra.
Cu2GeS3 is Enargite-like structured and crystallizes in the monoclinic Cc 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(1)S4 tetrahedra, corners with five equivalent Cu(2)S4 tetrahedra, and corners with five equivalent Ge(1)S4 tetrahedra. The Cu(1)-S(1) bond length is 2.28 Å. The Cu(1)-S(3) bond length is 2.31 Å. Both Cu(1)-S(2) bond lengths are 2.28 Å. In the second Cu site, Cu(2) is bonded to one S(2), one S(3), and two equivalent S(1) atoms to form CuS4 tetrahedra that share corners with two equivalent Cu(2)S4 tetrahedra, corners with five equivalent Cu(1)S4 tetrahedra, and corners with five equivalent Ge(1)S4 tetrahedra. The Cu(2)-S(2) bond length is 2.27 Å. The Cu(2)-S(3) bond length is 2.30 Å. There is one shorter (2.27 Å) and one longer (2.28 Å) Cu(2)-S(1) bond length. Ge(1) is bonded to one S(1), one S(2), and two equivalent S(3) atoms to form GeS4 tetrahedra that share corners with two equivalent Ge(1)S4 tetrahedra, corners with five equivalent Cu(1)S4 tetrahedra, and corners with five equivalent Cu(2)S4 tetrahedra. The Ge(1)-S(1) bond length is 2.21 Å. The Ge(1)-S(2) bond length is 2.21 Å. There is one shorter (2.32 Å) and one longer (2.35 Å) Ge(1)-S(3) bond length. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Cu(1), two equivalent Cu(2), and one Ge(1) atom to form SCu3Ge tetrahedra that share corners with two equivalent S(1)Cu3Ge tetrahedra, corners with five equivalent S(3)Cu2Ge2 tetrahedra, and corners with five equivalent S(2)Cu3Ge tetrahedra. In the second S site, S(2) is bonded to one Cu(2), two equivalent Cu(1), and one Ge(1) atom to form SCu3Ge tetrahedra that share corners with two equivalent S(2)Cu3Ge tetrahedra, corners with five equivalent S(3)Cu2Ge2 tetrahedra, and corners with five equivalent S(1)Cu3Ge tetrahedra. In the third S site, S(3) is bonded to one Cu(1), one Cu(2), and two equivalent Ge(1) atoms to form SCu2Ge2 tetrahedra that share corners with two equivalent S(3)Cu2Ge2 tetrahedra, corners with five equivalent S(1)Cu3Ge tetrahedra, and corners with five equivalent S(2)Cu3Ge tetrahedra.