Cs2Sb4S7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 10-coordinate geometry to one Sb(3), one S(1), one S(3), one S(4), one S(5), two equivalent S(7), and three equivalent S(6) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one S(1), one S(3), one S(4), one S(5), one S(7), and three equivalent S(2) atoms. There are four inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 3-coordinate geometry to one S(1), one S(2), and one S(7) atom. In the second Sb site, Sb(2) is bonded in a distorted see-saw-like geometry to one S(1), one S(2), one S(3), and one S(4) atom. In the third Sb site, Sb(3) is bonded in a 4-coordinate geometry to one Cs(1), one S(3), one S(4), one S(5), and one S(6) atom. In the fourth Sb site, Sb(4) is bonded in a 3-coordinate geometry to one S(5), one S(6), and one S(7) atom. There are seven inequivalent S sites. In the first S site, S(3) is bonded in a distorted see-saw-like geometry to one Cs(1), one Cs(2), one Sb(2), and one Sb(3) atom. In the second S site, S(4) is bonded in a distorted rectangular see-saw-like geometry to one Cs(1), one Cs(2), one Sb(2), and one Sb(3) atom. In the third S site, S(5) is bonded in a 3-coordinate geometry to one Cs(1), one Cs(2), one Sb(3), and one Sb(4) atom. In the fourth S site, S(6) is bonded in a 5-coordinate geometry to three equivalent Cs(1), one Sb(3), and one Sb(4) atom. In the fifth S site, S(7) is bonded in a 5-coordinate geometry to one Cs(2), two equivalent Cs(1), one Sb(1), and one Sb(4) atom. In the sixth S site, S(1) is bonded in a distorted rectangular see-saw-like geometry to one Cs(1), one Cs(2), one Sb(1), and one Sb(2) atom. In the seventh S site, S(2) is bonded in a 5-coordinate geometry to three equivalent Cs(2), one Sb(1), and one Sb(2) atom.
Cs2Sb4S7 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 10-coordinate geometry to one Sb(3), one S(1), one S(3), one S(4), one S(5), two equivalent S(7), and three equivalent S(6) atoms. The Cs(1)-Sb(3) bond length is 3.98 Å. The Cs(1)-S(1) bond length is 3.54 Å. The Cs(1)-S(3) bond length is 3.54 Å. The Cs(1)-S(4) bond length is 3.56 Å. The Cs(1)-S(5) bond length is 4.13 Å. There is one shorter (3.60 Å) and one longer (3.77 Å) Cs(1)-S(7) bond length. There are a spread of Cs(1)-S(6) bond distances ranging from 3.70-3.90 Å. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one S(1), one S(3), one S(4), one S(5), one S(7), and three equivalent S(2) atoms. The Cs(2)-S(1) bond length is 3.73 Å. The Cs(2)-S(3) bond length is 3.66 Å. The Cs(2)-S(4) bond length is 3.57 Å. The Cs(2)-S(5) bond length is 3.64 Å. The Cs(2)-S(7) bond length is 3.56 Å. There are a spread of Cs(2)-S(2) bond distances ranging from 3.63-4.06 Å. There are four inequivalent Sb sites. In the first Sb site, Sb(1) is bonded in a 3-coordinate geometry to one S(1), one S(2), and one S(7) atom. The Sb(1)-S(1) bond length is 2.39 Å. The Sb(1)-S(2) bond length is 2.52 Å. The Sb(1)-S(7) bond length is 2.48 Å. In the second Sb site, Sb(2) is bonded in a distorted see-saw-like geometry to one S(1), one S(2), one S(3), and one S(4) atom. The Sb(2)-S(1) bond length is 2.77 Å. The Sb(2)-S(2) bond length is 2.48 Å. The Sb(2)-S(3) bond length is 2.48 Å. The Sb(2)-S(4) bond length is 2.65 Å. In the third Sb site, Sb(3) is bonded in a 4-coordinate geometry to one Cs(1), one S(3), one S(4), one S(5), and one S(6) atom. The Sb(3)-S(3) bond length is 2.47 Å. The Sb(3)-S(4) bond length is 2.55 Å. The Sb(3)-S(5) bond length is 2.47 Å. The Sb(3)-S(6) bond length is 2.94 Å. In the fourth Sb site, Sb(4) is bonded in a 3-coordinate geometry to one S(5), one S(6), and one S(7) atom. The Sb(4)-S(5) bond length is 2.52 Å. The Sb(4)-S(6) bond length is 2.37 Å. The Sb(4)-S(7) bond length is 2.51 Å. There are seven inequivalent S sites. In the first S site, S(3) is bonded in a distorted see-saw-like geometry to one Cs(1), one Cs(2), one Sb(2), and one Sb(3) atom. In the second S site, S(4) is bonded in a distorted rectangular see-saw-like geometry to one Cs(1), one Cs(2), one Sb(2), and one Sb(3) atom. In the third S site, S(5) is bonded in a 3-coordinate geometry to one Cs(1), one Cs(2), one Sb(3), and one Sb(4) atom. In the fourth S site, S(6) is bonded in a 5-coordinate geometry to three equivalent Cs(1), one Sb(3), and one Sb(4) atom. In the fifth S site, S(7) is bonded in a 5-coordinate geometry to one Cs(2), two equivalent Cs(1), one Sb(1), and one Sb(4) atom. In the sixth S site, S(1) is bonded in a distorted rectangular see-saw-like geometry to one Cs(1), one Cs(2), one Sb(1), and one Sb(2) atom. In the seventh S site, S(2) is bonded in a 5-coordinate geometry to three equivalent Cs(2), one Sb(1), and one Sb(2) atom.