Cu2SnTe3 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 Te(1), one Te(3), and two equivalent Te(2) atoms to form CuTe4 tetrahedra that share corners with two equivalent Cu(1)Te4 tetrahedra, corners with five equivalent Cu(2)Te4 tetrahedra, and corners with five equivalent Sn(1)Te4 tetrahedra. In the second Cu site, Cu(2) is bonded to one Te(1), one Te(2), and two equivalent Te(3) atoms to form CuTe4 tetrahedra that share corners with two equivalent Cu(2)Te4 tetrahedra, corners with five equivalent Cu(1)Te4 tetrahedra, and corners with five equivalent Sn(1)Te4 tetrahedra. Sn(1) is bonded to one Te(2), one Te(3), and two equivalent Te(1) atoms to form SnTe4 tetrahedra that share corners with two equivalent Sn(1)Te4 tetrahedra, corners with five equivalent Cu(1)Te4 tetrahedra, and corners with five equivalent Cu(2)Te4 tetrahedra. There are three inequivalent Te sites. In the first Te site, Te(1) is bonded to one Cu(1), one Cu(2), and two equivalent Sn(1) atoms to form TeCu2Sn2 tetrahedra that share corners with two equivalent Te(1)Cu2Sn2 tetrahedra, corners with five equivalent Te(2)Cu3Sn tetrahedra, and corners with five equivalent Te(3)Cu3Sn tetrahedra. In the second Te site, Te(2) is bonded to one Cu(2), two equivalent Cu(1), and one Sn(1) atom to form TeCu3Sn tetrahedra that share corners with two equivalent Te(2)Cu3Sn tetrahedra, corners with five equivalent Te(1)Cu2Sn2 tetrahedra, and corners with five equivalent Te(3)Cu3Sn tetrahedra. In the third Te site, Te(3) is bonded to one Cu(1), two equivalent Cu(2), and one Sn(1) atom to form TeCu3Sn tetrahedra that share corners with two equivalent Te(3)Cu3Sn tetrahedra, corners with five equivalent Te(1)Cu2Sn2 tetrahedra, and corners with five equivalent Te(2)Cu3Sn tetrahedra.
Cu2SnTe3 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 Te(1), one Te(3), and two equivalent Te(2) atoms to form CuTe4 tetrahedra that share corners with two equivalent Cu(1)Te4 tetrahedra, corners with five equivalent Cu(2)Te4 tetrahedra, and corners with five equivalent Sn(1)Te4 tetrahedra. The Cu(1)-Te(1) bond length is 2.60 Å. The Cu(1)-Te(3) bond length is 2.59 Å. There is one shorter (2.59 Å) and one longer (2.61 Å) Cu(1)-Te(2) bond length. In the second Cu site, Cu(2) is bonded to one Te(1), one Te(2), and two equivalent Te(3) atoms to form CuTe4 tetrahedra that share corners with two equivalent Cu(2)Te4 tetrahedra, corners with five equivalent Cu(1)Te4 tetrahedra, and corners with five equivalent Sn(1)Te4 tetrahedra. The Cu(2)-Te(1) bond length is 2.59 Å. The Cu(2)-Te(2) bond length is 2.59 Å. There is one shorter (2.58 Å) and one longer (2.59 Å) Cu(2)-Te(3) bond length. Sn(1) is bonded to one Te(2), one Te(3), and two equivalent Te(1) atoms to form SnTe4 tetrahedra that share corners with two equivalent Sn(1)Te4 tetrahedra, corners with five equivalent Cu(1)Te4 tetrahedra, and corners with five equivalent Cu(2)Te4 tetrahedra. The Sn(1)-Te(2) bond length is 2.82 Å. The Sn(1)-Te(3) bond length is 2.82 Å. There is one shorter (2.87 Å) and one longer (2.89 Å) Sn(1)-Te(1) bond length. There are three inequivalent Te sites. In the first Te site, Te(1) is bonded to one Cu(1), one Cu(2), and two equivalent Sn(1) atoms to form TeCu2Sn2 tetrahedra that share corners with two equivalent Te(1)Cu2Sn2 tetrahedra, corners with five equivalent Te(2)Cu3Sn tetrahedra, and corners with five equivalent Te(3)Cu3Sn tetrahedra. In the second Te site, Te(2) is bonded to one Cu(2), two equivalent Cu(1), and one Sn(1) atom to form TeCu3Sn tetrahedra that share corners with two equivalent Te(2)Cu3Sn tetrahedra, corners with five equivalent Te(1)Cu2Sn2 tetrahedra, and corners with five equivalent Te(3)Cu3Sn tetrahedra. In the third Te site, Te(3) is bonded to one Cu(1), two equivalent Cu(2), and one Sn(1) atom to form TeCu3Sn tetrahedra that share corners with two equivalent Te(3)Cu3Sn tetrahedra, corners with five equivalent Te(1)Cu2Sn2 tetrahedra, and corners with five equivalent Te(2)Cu3Sn tetrahedra.