Nb4FeS8 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to six equivalent S(2) atoms. In the second Nb site, Nb(2) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form distorted NbS6 pentagonal pyramids that share corners with four equivalent Fe(1)S6 octahedra and edges with four equivalent Nb(2)S6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. Fe(1) is bonded to six equivalent S(2) atoms to form FeS6 octahedra that share corners with twelve equivalent Nb(2)S6 pentagonal pyramids. There are two inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to three equivalent Nb(2) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Nb(1), two equivalent Nb(2), and one Fe(1) atom.
Nb4FeS8 crystallizes in the hexagonal P6_3/mmc space group. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded in a 6-coordinate geometry to six equivalent S(2) atoms. All Nb(1)-S(2) bond lengths are 2.50 Å. In the second Nb site, Nb(2) is bonded to two equivalent S(1) and four equivalent S(2) atoms to form distorted NbS6 pentagonal pyramids that share corners with four equivalent Fe(1)S6 octahedra and edges with four equivalent Nb(2)S6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 48°. Both Nb(2)-S(1) bond lengths are 2.46 Å. All Nb(2)-S(2) bond lengths are 2.52 Å. Fe(1) is bonded to six equivalent S(2) atoms to form FeS6 octahedra that share corners with twelve equivalent Nb(2)S6 pentagonal pyramids. All Fe(1)-S(2) bond lengths are 2.45 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a distorted T-shaped geometry to three equivalent Nb(2) atoms. In the second S site, S(2) is bonded in a rectangular see-saw-like geometry to one Nb(1), two equivalent Nb(2), and one Fe(1) atom.