FePb4Sb6S14 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to two equivalent S(5) and four equivalent S(6) atoms to form FeS6 octahedra that share corners with two equivalent Pb(2)S6 octahedra and edges with two equivalent Fe(1)S6 octahedra. The corner-sharing octahedral tilt angles are 36°. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 5-coordinate geometry to one S(2), two equivalent S(6), and two equivalent S(7) atoms. In the second Pb site, Pb(2) is bonded to one S(3), one S(5), two equivalent S(4), and two equivalent S(7) atoms to form distorted PbS6 octahedra that share  a cornercorner with one Fe(1)S6 octahedra, edges with two equivalent Pb(2)S6 octahedra, and edges with two equivalent Sb(2)S5 square pyramids. The corner-sharing octahedral tilt angles are 36°. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 5-coordinate geometry to one S(6), two equivalent S(2), and two equivalent S(5) atoms. In the second Sb site, Sb(2) is bonded to one S(7), two equivalent S(2), and two equivalent S(3) atoms to form distorted SbS5 square pyramids that share edges with two equivalent Pb(2)S6 octahedra and edges with two equivalent Sb(2)S5 square pyramids. In the third Sb site, Sb(3) is bonded in a distorted rectangular see-saw-like geometry to one S(4), two equivalent S(1), and two equivalent S(3) atoms. There are seven inequivalent S sites. In the first S site, S(5) is bonded in a 4-coordinate geometry to one Fe(1), one Pb(2), and two equivalent Sb(1) atoms. In the second S site, S(6) is bonded to two equivalent Fe(1), two equivalent Pb(1), and one Sb(1) atom to form distorted SFe2SbPb2 square pyramids that share corners with two equivalent S(6)Fe2SbPb2 square pyramids, edges with two equivalent S(2)Sb4Pb square pyramids, and edges with three equivalent S(6)Fe2SbPb2 square pyramids. In the third S site, S(7) is bonded in a 5-coordinate geometry to two equivalent Pb(1), two equivalent Pb(2), and one Sb(2) atom. In the fourth S site, S(1) is bonded in a distorted water-like geometry to two equivalent Sb(3) atoms. In the fifth S site, S(2) is bonded to one Pb(1), two equivalent Sb(1), and two equivalent Sb(2) atoms to form distorted SSb4Pb square pyramids that share edges with two equivalent S(6)Fe2SbPb2 square pyramids and edges with two equivalent S(2)Sb4Pb square pyramids. In the sixth S site, S(3) is bonded in a 5-coordinate geometry to one Pb(2), two equivalent Sb(2), and two equivalent Sb(3) atoms. In the seventh S site, S(4) is bonded in a 3-coordinate geometry to two equivalent Pb(2) and one Sb(3) atom.
FePb4Sb6S14 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to two equivalent S(5) and four equivalent S(6) atoms to form FeS6 octahedra that share corners with two equivalent Pb(2)S6 octahedra and edges with two equivalent Fe(1)S6 octahedra. The corner-sharing octahedral tilt angles are 36°. Both Fe(1)-S(5) bond lengths are 2.36 Å. There are two shorter (2.62 Å) and two longer (2.69 Å) Fe(1)-S(6) bond lengths. There are two inequivalent Pb sites. In the first Pb site, Pb(1) is bonded in a 5-coordinate geometry to one S(2), two equivalent S(6), and two equivalent S(7) atoms. The Pb(1)-S(2) bond length is 3.01 Å. There is one shorter (3.06 Å) and one longer (3.07 Å) Pb(1)-S(6) bond length. Both Pb(1)-S(7) bond lengths are 2.97 Å. In the second Pb site, Pb(2) is bonded to one S(3), one S(5), two equivalent S(4), and two equivalent S(7) atoms to form distorted PbS6 octahedra that share  a cornercorner with one Fe(1)S6 octahedra, edges with two equivalent Pb(2)S6 octahedra, and edges with two equivalent Sb(2)S5 square pyramids. The corner-sharing octahedral tilt angles are 36°. The Pb(2)-S(3) bond length is 2.95 Å. The Pb(2)-S(5) bond length is 3.08 Å. Both Pb(2)-S(4) bond lengths are 2.89 Å. There is one shorter (3.07 Å) and one longer (3.12 Å) Pb(2)-S(7) bond length. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 5-coordinate geometry to one S(6), two equivalent S(2), and two equivalent S(5) atoms. The Sb(1)-S(6) bond length is 2.49 Å. There is one shorter (2.70 Å) and one longer (3.13 Å) Sb(1)-S(2) bond length. There is one shorter (2.52 Å) and one longer (2.89 Å) Sb(1)-S(5) bond length. In the second Sb site, Sb(2) is bonded to one S(7), two equivalent S(2), and two equivalent S(3) atoms to form distorted SbS5 square pyramids that share edges with two equivalent Pb(2)S6 octahedra and edges with two equivalent Sb(2)S5 square pyramids. The Sb(2)-S(7) bond length is 2.48 Å. There is one shorter (2.63 Å) and one longer (3.07 Å) Sb(2)-S(2) bond length. There is one shorter (2.57 Å) and one longer (3.04 Å) Sb(2)-S(3) bond length. In the third Sb site, Sb(3) is bonded in a distorted rectangular see-saw-like geometry to one S(4), two equivalent S(1), and two equivalent S(3) atoms. The Sb(3)-S(4) bond length is 2.47 Å. There is one shorter (2.52 Å) and one longer (2.74 Å) Sb(3)-S(1) bond length. There is one shorter (2.95 Å) and one longer (3.19 Å) Sb(3)-S(3) bond length. There are seven inequivalent S sites. In the first S site, S(5) is bonded in a 4-coordinate geometry to one Fe(1), one Pb(2), and two equivalent Sb(1) atoms. In the second S site, S(6) is bonded to two equivalent Fe(1), two equivalent Pb(1), and one Sb(1) atom to form distorted SFe2SbPb2 square pyramids that share corners with two equivalent S(6)Fe2SbPb2 square pyramids, edges with two equivalent S(2)Sb4Pb square pyramids, and edges with three equivalent S(6)Fe2SbPb2 square pyramids. In the third S site, S(7) is bonded in a 5-coordinate geometry to two equivalent Pb(1), two equivalent Pb(2), and one Sb(2) atom. In the fourth S site, S(1) is bonded in a distorted water-like geometry to two equivalent Sb(3) atoms. In the fifth S site, S(2) is bonded to one Pb(1), two equivalent Sb(1), and two equivalent Sb(2) atoms to form distorted SSb4Pb square pyramids that share edges with two equivalent S(6)Fe2SbPb2 square pyramids and edges with two equivalent S(2)Sb4Pb square pyramids. In the sixth S site, S(3) is bonded in a 5-coordinate geometry to one Pb(2), two equivalent Sb(2), and two equivalent Sb(3) atoms. In the seventh S site, S(4) is bonded in a 3-coordinate geometry to two equivalent Pb(2) and one Sb(3) atom.