FeS2 is trigonal omega-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to six equivalent S(1) atoms to form edge-sharing FeS6 octahedra. In the second Fe site, Fe(2) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form edge-sharing FeS6 octahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to one Fe(1) and two equivalent Fe(2) atoms. In the second S site, S(2) is bonded in a distorted T-shaped geometry to three equivalent Fe(2) atoms.
FeS2 is trigonal omega-like structured and crystallizes in the trigonal R-3m space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to six equivalent S(1) atoms to form edge-sharing FeS6 octahedra. All Fe(1)-S(1) bond lengths are 2.28 Å. In the second Fe site, Fe(2) is bonded to two equivalent S(2) and four equivalent S(1) atoms to form edge-sharing FeS6 octahedra. Both Fe(2)-S(2) bond lengths are 2.27 Å. All Fe(2)-S(1) bond lengths are 2.27 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to one Fe(1) and two equivalent Fe(2) atoms. In the second S site, S(2) is bonded in a distorted T-shaped geometry to three equivalent Fe(2) atoms.