Cu3SbSe4 is Enargite-like structured and crystallizes in the tetragonal I-42m space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Cu(2)Se4 tetrahedra, and corners with four equivalent Sb(1)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded to four equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with four equivalent Sb(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. Sb(1) is bonded to four equivalent Se(1) atoms to form SbSe4 tetrahedra that share corners with four equivalent Cu(2)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. Se(1) is bonded to one Cu(2), two equivalent Cu(1), and one Sb(1) atom to form corner-sharing SeCu3Sb tetrahedra.
Cu3SbSe4 is Enargite-like structured and crystallizes in the tetragonal I-42m space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to four equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with four equivalent Cu(1)Se4 tetrahedra, corners with four equivalent Cu(2)Se4 tetrahedra, and corners with four equivalent Sb(1)Se4 tetrahedra. All Cu(1)-Se(1) bond lengths are 2.40 Å. In the second Cu site, Cu(2) is bonded to four equivalent Se(1) atoms to form CuSe4 tetrahedra that share corners with four equivalent Sb(1)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. All Cu(2)-Se(1) bond lengths are 2.41 Å. Sb(1) is bonded to four equivalent Se(1) atoms to form SbSe4 tetrahedra that share corners with four equivalent Cu(2)Se4 tetrahedra and corners with eight equivalent Cu(1)Se4 tetrahedra. All Sb(1)-Se(1) bond lengths are 2.61 Å. Se(1) is bonded to one Cu(2), two equivalent Cu(1), and one Sb(1) atom to form corner-sharing SeCu3Sb tetrahedra.