CuFe2S3 is Enargite-like structured and crystallizes in the trigonal P3m1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one S(1) and three equivalent S(2) atoms to form FeS4 tetrahedra that share corners with three equivalent Fe(2)S4 tetrahedra, corners with three equivalent Cu(1)S4 tetrahedra, and corners with six equivalent Fe(1)S4 tetrahedra. In the second Fe site, Fe(2) is bonded to one S(2) and three equivalent S(3) atoms to form FeS4 tetrahedra that share corners with three equivalent Fe(1)S4 tetrahedra, corners with three equivalent Cu(1)S4 tetrahedra, and corners with six equivalent Fe(2)S4 tetrahedra. Cu(1) is bonded to one S(3) and three equivalent S(1) atoms to form CuS4 tetrahedra that share corners with three equivalent Fe(1)S4 tetrahedra, corners with three equivalent Fe(2)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 Fe(1) and three equivalent Cu(1) atoms to form SFeCu3 tetrahedra that share corners with three equivalent S(3)Fe3Cu tetrahedra, corners with three equivalent S(2)Fe4 tetrahedra, and corners with six equivalent S(1)FeCu3 tetrahedra. In the second S site, S(2) is bonded to one Fe(2) and three equivalent Fe(1) atoms to form SFe4 tetrahedra that share corners with three equivalent S(3)Fe3Cu tetrahedra, corners with three equivalent S(1)FeCu3 tetrahedra, and corners with six equivalent S(2)Fe4 tetrahedra. In the third S site, S(3) is bonded to three equivalent Fe(2) and one Cu(1) atom to form SFe3Cu tetrahedra that share corners with three equivalent S(2)Fe4 tetrahedra, corners with three equivalent S(1)FeCu3 tetrahedra, and corners with six equivalent S(3)Fe3Cu tetrahedra.
CuFe2S3 is Enargite-like structured and crystallizes in the trigonal P3m1 space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one S(1) and three equivalent S(2) atoms to form FeS4 tetrahedra that share corners with three equivalent Fe(2)S4 tetrahedra, corners with three equivalent Cu(1)S4 tetrahedra, and corners with six equivalent Fe(1)S4 tetrahedra. The Fe(1)-S(1) bond length is 2.22 Å. All Fe(1)-S(2) bond lengths are 2.33 Å. In the second Fe site, Fe(2) is bonded to one S(2) and three equivalent S(3) atoms to form FeS4 tetrahedra that share corners with three equivalent Fe(1)S4 tetrahedra, corners with three equivalent Cu(1)S4 tetrahedra, and corners with six equivalent Fe(2)S4 tetrahedra. The Fe(2)-S(2) bond length is 2.33 Å. All Fe(2)-S(3) bond lengths are 2.32 Å. Cu(1) is bonded to one S(3) and three equivalent S(1) atoms to form CuS4 tetrahedra that share corners with three equivalent Fe(1)S4 tetrahedra, corners with three equivalent Fe(2)S4 tetrahedra, and corners with six equivalent Cu(1)S4 tetrahedra. The Cu(1)-S(3) bond length is 2.32 Å. All Cu(1)-S(1) bond lengths are 2.26 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded to one Fe(1) and three equivalent Cu(1) atoms to form SFeCu3 tetrahedra that share corners with three equivalent S(3)Fe3Cu tetrahedra, corners with three equivalent S(2)Fe4 tetrahedra, and corners with six equivalent S(1)FeCu3 tetrahedra. In the second S site, S(2) is bonded to one Fe(2) and three equivalent Fe(1) atoms to form SFe4 tetrahedra that share corners with three equivalent S(3)Fe3Cu tetrahedra, corners with three equivalent S(1)FeCu3 tetrahedra, and corners with six equivalent S(2)Fe4 tetrahedra. In the third S site, S(3) is bonded to three equivalent Fe(2) and one Cu(1) atom to form SFe3Cu tetrahedra that share corners with three equivalent S(2)Fe4 tetrahedra, corners with three equivalent S(1)FeCu3 tetrahedra, and corners with six equivalent S(3)Fe3Cu tetrahedra.