FeCdS2 is Enargite-like structured and crystallizes in the trigonal P3m1 space group. Fe(1) is bonded to one S(2) and three equivalent S(1) atoms to form FeS4 tetrahedra that share corners with six equivalent Fe(1)S4 tetrahedra and corners with six equivalent Cd(1)S4 tetrahedra. Cd(1) is bonded to one S(1) and three equivalent S(2) atoms to form CdS4 tetrahedra that share corners with six equivalent Fe(1)S4 tetrahedra and corners with six equivalent Cd(1)S4 tetrahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Fe(1) and one Cd(1) atom to form SCdFe3 tetrahedra that share corners with six equivalent S(2)Cd3Fe tetrahedra and corners with six equivalent S(1)CdFe3 tetrahedra. In the second S site, S(2) is bonded to one Fe(1) and three equivalent Cd(1) atoms to form SCd3Fe tetrahedra that share corners with six equivalent S(2)Cd3Fe tetrahedra and corners with six equivalent S(1)CdFe3 tetrahedra.
FeCdS2 is Enargite-like structured and crystallizes in the trigonal P3m1 space group. Fe(1) is bonded to one S(2) and three equivalent S(1) atoms to form FeS4 tetrahedra that share corners with six equivalent Fe(1)S4 tetrahedra and corners with six equivalent Cd(1)S4 tetrahedra. The Fe(1)-S(2) bond length is 2.30 Å. All Fe(1)-S(1) bond lengths are 2.40 Å. Cd(1) is bonded to one S(1) and three equivalent S(2) atoms to form CdS4 tetrahedra that share corners with six equivalent Fe(1)S4 tetrahedra and corners with six equivalent Cd(1)S4 tetrahedra. The Cd(1)-S(1) bond length is 2.55 Å. All Cd(1)-S(2) bond lengths are 2.54 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded to three equivalent Fe(1) and one Cd(1) atom to form SCdFe3 tetrahedra that share corners with six equivalent S(2)Cd3Fe tetrahedra and corners with six equivalent S(1)CdFe3 tetrahedra. In the second S site, S(2) is bonded to one Fe(1) and three equivalent Cd(1) atoms to form SCd3Fe tetrahedra that share corners with six equivalent S(2)Cd3Fe tetrahedra and corners with six equivalent S(1)CdFe3 tetrahedra.