Pr4CrS7 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form face-sharing PrS6 octahedra. In the second Pr site, Pr(2) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(3), one S(4), one S(7), and two equivalent S(5) atoms. In the third Pr site, Pr(3) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(3), one S(5), one S(7), and two equivalent S(6) atoms. In the fourth Pr site, Pr(4) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(3), one S(6), one S(7), and two equivalent S(4) atoms. Cr(1) is bonded in a tetrahedral geometry to one S(4), one S(5), one S(6), and one S(7) atom. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to one Pr(2), one Pr(3), one Pr(4), and two equivalent Pr(1) atoms. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Pr(2), one Pr(3), one Pr(4), and two equivalent Pr(1) atoms. In the third S site, S(3) is bonded in a 5-coordinate geometry to one Pr(2), one Pr(3), one Pr(4), and two equivalent Pr(1) atoms. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Pr(2), two equivalent Pr(4), and one Cr(1) atom. In the fifth S site, S(5) is bonded in a rectangular see-saw-like geometry to one Pr(3), two equivalent Pr(2), and one Cr(1) atom. In the sixth S site, S(6) is bonded in a rectangular see-saw-like geometry to one Pr(4), two equivalent Pr(3), and one Cr(1) atom. In the seventh S site, S(7) is bonded in a distorted tetrahedral geometry to one Pr(2), one Pr(3), one Pr(4), and one Cr(1) atom.
Pr4CrS7 crystallizes in the monoclinic P2_1 space group. There are four inequivalent Pr sites. In the first Pr site, Pr(1) is bonded to two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms to form face-sharing PrS6 octahedra. There is one shorter (2.80 Å) and one longer (2.84 Å) Pr(1)-S(1) bond length. There is one shorter (2.80 Å) and one longer (2.84 Å) Pr(1)-S(2) bond length. There is one shorter (2.79 Å) and one longer (2.84 Å) Pr(1)-S(3) bond length. In the second Pr site, Pr(2) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(3), one S(4), one S(7), and two equivalent S(5) atoms. The Pr(2)-S(1) bond length is 3.17 Å. The Pr(2)-S(2) bond length is 3.10 Å. The Pr(2)-S(3) bond length is 3.20 Å. The Pr(2)-S(4) bond length is 2.93 Å. The Pr(2)-S(7) bond length is 2.82 Å. There is one shorter (2.76 Å) and one longer (3.04 Å) Pr(2)-S(5) bond length. In the third Pr site, Pr(3) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(3), one S(5), one S(7), and two equivalent S(6) atoms. The Pr(3)-S(1) bond length is 3.21 Å. The Pr(3)-S(2) bond length is 3.17 Å. The Pr(3)-S(3) bond length is 3.10 Å. The Pr(3)-S(5) bond length is 2.94 Å. The Pr(3)-S(7) bond length is 2.81 Å. There is one shorter (2.77 Å) and one longer (3.05 Å) Pr(3)-S(6) bond length. In the fourth Pr site, Pr(4) is bonded in a 7-coordinate geometry to one S(1), one S(2), one S(3), one S(6), one S(7), and two equivalent S(4) atoms. The Pr(4)-S(1) bond length is 3.10 Å. The Pr(4)-S(2) bond length is 3.20 Å. The Pr(4)-S(3) bond length is 3.17 Å. The Pr(4)-S(6) bond length is 2.92 Å. The Pr(4)-S(7) bond length is 2.82 Å. There is one shorter (2.77 Å) and one longer (3.06 Å) Pr(4)-S(4) bond length. Cr(1) is bonded in a tetrahedral geometry to one S(4), one S(5), one S(6), and one S(7) atom. The Cr(1)-S(4) bond length is 2.32 Å. The Cr(1)-S(5) bond length is 2.33 Å. The Cr(1)-S(6) bond length is 2.33 Å. The Cr(1)-S(7) bond length is 2.37 Å. There are seven inequivalent S sites. In the first S site, S(1) is bonded in a 5-coordinate geometry to one Pr(2), one Pr(3), one Pr(4), and two equivalent Pr(1) atoms. In the second S site, S(2) is bonded in a 5-coordinate geometry to one Pr(2), one Pr(3), one Pr(4), and two equivalent Pr(1) atoms. In the third S site, S(3) is bonded in a 5-coordinate geometry to one Pr(2), one Pr(3), one Pr(4), and two equivalent Pr(1) atoms. In the fourth S site, S(4) is bonded in a rectangular see-saw-like geometry to one Pr(2), two equivalent Pr(4), and one Cr(1) atom. In the fifth S site, S(5) is bonded in a rectangular see-saw-like geometry to one Pr(3), two equivalent Pr(2), and one Cr(1) atom. In the sixth S site, S(6) is bonded in a rectangular see-saw-like geometry to one Pr(4), two equivalent Pr(3), and one Cr(1) atom. In the seventh S site, S(7) is bonded in a distorted tetrahedral geometry to one Pr(2), one Pr(3), one Pr(4), and one Cr(1) atom.