Ni17S18 crystallizes in the trigonal R-3m space group. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form a mixture of corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. In the second Ni site, Ni(2) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form a mixture of corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. In the third Ni site, Ni(3) is bonded to three equivalent S(2) and three equivalent S(3) atoms to form a mixture of distorted corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. In the fourth Ni site, Ni(4) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form a mixture of corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. In the fifth Ni site, Ni(5) is bonded to six equivalent S(1) atoms to form a mixture of corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles are 50°. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to one Ni(1), one Ni(5), two equivalent Ni(2), and two equivalent Ni(4) atoms. In the second S site, S(2) is bonded in a 6-coordinate geometry to one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent Ni(4) atoms. In the third S site, S(3) is bonded to one Ni(3), two equivalent Ni(2), and two equivalent Ni(4) atoms to form distorted corner-sharing SNi5 square pyramids.
Ni17S18 crystallizes in the trigonal R-3m space group. There are five inequivalent Ni sites. In the first Ni site, Ni(1) is bonded to three equivalent S(1) and three equivalent S(2) atoms to form a mixture of corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. All Ni(1)-S(1) bond lengths are 2.35 Å. All Ni(1)-S(2) bond lengths are 2.34 Å. In the second Ni site, Ni(2) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form a mixture of corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. Both Ni(2)-S(1) bond lengths are 2.43 Å. Both Ni(2)-S(2) bond lengths are 2.40 Å. Both Ni(2)-S(3) bond lengths are 2.30 Å. In the third Ni site, Ni(3) is bonded to three equivalent S(2) and three equivalent S(3) atoms to form a mixture of distorted corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles range from 46-53°. All Ni(3)-S(2) bond lengths are 2.45 Å. All Ni(3)-S(3) bond lengths are 2.27 Å. In the fourth Ni site, Ni(4) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form a mixture of corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles range from 48-52°. Both Ni(4)-S(1) bond lengths are 2.36 Å. Both Ni(4)-S(2) bond lengths are 2.40 Å. Both Ni(4)-S(3) bond lengths are 2.32 Å. In the fifth Ni site, Ni(5) is bonded to six equivalent S(1) atoms to form a mixture of corner, edge, and face-sharing NiS6 octahedra. The corner-sharing octahedral tilt angles are 50°. All Ni(5)-S(1) bond lengths are 2.37 Å. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to one Ni(1), one Ni(5), two equivalent Ni(2), and two equivalent Ni(4) atoms. In the second S site, S(2) is bonded in a 6-coordinate geometry to one Ni(1), one Ni(3), two equivalent Ni(2), and two equivalent Ni(4) atoms. In the third S site, S(3) is bonded to one Ni(3), two equivalent Ni(2), and two equivalent Ni(4) atoms to form distorted corner-sharing SNi5 square pyramids.