Ni3S2 crystallizes in the trigonal R3m space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to three equivalent S(1) atoms. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to one S(2) and three equivalent S(1) atoms. In the third Ni site, Ni(3) is bonded in a distorted trigonal non-coplanar geometry to one S(1) and three equivalent S(2) atoms. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to one Ni(3), three equivalent Ni(1), and three equivalent Ni(2) atoms. In the second S site, S(2) is bonded to one Ni(2) and three equivalent Ni(3) atoms to form corner-sharing SNi4 tetrahedra.
Ni3S2 crystallizes in the trigonal R3m space group. There are three inequivalent Ni sites. In the first Ni site, Ni(1) is bonded in a 3-coordinate geometry to three equivalent S(1) atoms. All Ni(1)-S(1) bond lengths are 2.28 Å. In the second Ni site, Ni(2) is bonded in a 4-coordinate geometry to one S(2) and three equivalent S(1) atoms. The Ni(2)-S(2) bond length is 2.15 Å. All Ni(2)-S(1) bond lengths are 2.30 Å. In the third Ni site, Ni(3) is bonded in a distorted trigonal non-coplanar geometry to one S(1) and three equivalent S(2) atoms. The Ni(3)-S(1) bond length is 2.65 Å. All Ni(3)-S(2) bond lengths are 2.16 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to one Ni(3), three equivalent Ni(1), and three equivalent Ni(2) atoms. In the second S site, S(2) is bonded to one Ni(2) and three equivalent Ni(3) atoms to form corner-sharing SNi4 tetrahedra.