Pr3AsS5Cl2 crystallizes in the monoclinic Cc space group. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to one S(5), two equivalent S(1), two equivalent S(2), one Cl(1), and two equivalent Cl(2) atoms. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to one S(4), two equivalent S(1), two equivalent S(3), one Cl(2), and two equivalent Cl(1) atoms. In the third Pr site, Pr(3) is bonded in a 7-coordinate geometry to one S(3), two equivalent S(2), two equivalent S(4), and two equivalent S(5) atoms. As(1) is bonded in a 3-coordinate geometry to one S(3), one S(4), and one S(5) atom. There are five inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Pr(1) and two equivalent Pr(2) atoms to form SPr4 tetrahedra that share corners with two equivalent S(2)Pr4 tetrahedra, corners with two equivalent S(4)Pr3As trigonal pyramids, corners with two equivalent S(5)Pr3As trigonal pyramids,  an edgeedge with one S(2)Pr4 tetrahedra, and edges with two equivalent S(1)Pr4 tetrahedra. In the second S site, S(2) is bonded to two equivalent Pr(1) and two equivalent Pr(3) atoms to form SPr4 tetrahedra that share corners with two equivalent S(1)Pr4 tetrahedra, corners with two equivalent S(4)Pr3As trigonal pyramids, corners with four equivalent S(5)Pr3As trigonal pyramids,  an edgeedge with one S(1)Pr4 tetrahedra, edges with two equivalent S(2)Pr4 tetrahedra,  an edgeedge with one S(4)Pr3As trigonal pyramid, and  an edgeedge with one S(5)Pr3As trigonal pyramid. In the third S site, S(3) is bonded in a distorted see-saw-like geometry to one Pr(3), two equivalent Pr(2), and one As(1) atom. In the fourth S site, S(4) is bonded to one Pr(2), two equivalent Pr(3), and one As(1) atom to form SPr3As trigonal pyramids that share corners with two equivalent S(1)Pr4 tetrahedra, corners with two equivalent S(2)Pr4 tetrahedra, corners with two equivalent S(4)Pr3As trigonal pyramids, corners with three equivalent S(5)Pr3As trigonal pyramids,  an edgeedge with one S(2)Pr4 tetrahedra, and  an edgeedge with one S(5)Pr3As trigonal pyramid. In the fifth S site, S(5) is bonded to one Pr(1), two equivalent Pr(3), and one As(1) atom to form distorted SPr3As trigonal pyramids that share corners with two equivalent S(1)Pr4 tetrahedra, corners with four equivalent S(2)Pr4 tetrahedra, corners with two equivalent S(5)Pr3As trigonal pyramids, corners with three equivalent S(4)Pr3As trigonal pyramids,  an edgeedge with one S(2)Pr4 tetrahedra, and  an edgeedge with one S(4)Pr3As trigonal pyramid. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a 3-coordinate geometry to one Pr(1) and two equivalent Pr(2) atoms. In the second Cl site, Cl(2) is bonded in a 3-coordinate geometry to one Pr(2) and two equivalent Pr(1) atoms.
Pr3AsS5Cl2 crystallizes in the monoclinic Cc space group. There are three inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to one S(5), two equivalent S(1), two equivalent S(2), one Cl(1), and two equivalent Cl(2) atoms. The Pr(1)-S(5) bond length is 3.13 Å. There is one shorter (2.87 Å) and one longer (2.89 Å) Pr(1)-S(1) bond length. There is one shorter (2.87 Å) and one longer (2.98 Å) Pr(1)-S(2) bond length. The Pr(1)-Cl(1) bond length is 3.21 Å. There is one shorter (2.89 Å) and one longer (2.98 Å) Pr(1)-Cl(2) bond length. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to one S(4), two equivalent S(1), two equivalent S(3), one Cl(2), and two equivalent Cl(1) atoms. The Pr(2)-S(4) bond length is 3.02 Å. Both Pr(2)-S(1) bond lengths are 2.82 Å. There is one shorter (3.01 Å) and one longer (3.04 Å) Pr(2)-S(3) bond length. The Pr(2)-Cl(2) bond length is 3.32 Å. There is one shorter (2.89 Å) and one longer (2.94 Å) Pr(2)-Cl(1) bond length. In the third Pr site, Pr(3) is bonded in a 7-coordinate geometry to one S(3), two equivalent S(2), two equivalent S(4), and two equivalent S(5) atoms. The Pr(3)-S(3) bond length is 3.03 Å. There is one shorter (2.82 Å) and one longer (2.83 Å) Pr(3)-S(2) bond length. There is one shorter (2.93 Å) and one longer (3.05 Å) Pr(3)-S(4) bond length. There is one shorter (2.91 Å) and one longer (2.99 Å) Pr(3)-S(5) bond length. As(1) is bonded in a 3-coordinate geometry to one S(3), one S(4), and one S(5) atom. The As(1)-S(3) bond length is 2.31 Å. The As(1)-S(4) bond length is 2.30 Å. The As(1)-S(5) bond length is 2.30 Å. There are five inequivalent S sites. In the first S site, S(1) is bonded to two equivalent Pr(1) and two equivalent Pr(2) atoms to form SPr4 tetrahedra that share corners with two equivalent S(2)Pr4 tetrahedra, corners with two equivalent S(4)Pr3As trigonal pyramids, corners with two equivalent S(5)Pr3As trigonal pyramids,  an edgeedge with one S(2)Pr4 tetrahedra, and edges with two equivalent S(1)Pr4 tetrahedra. In the second S site, S(2) is bonded to two equivalent Pr(1) and two equivalent Pr(3) atoms to form SPr4 tetrahedra that share corners with two equivalent S(1)Pr4 tetrahedra, corners with two equivalent S(4)Pr3As trigonal pyramids, corners with four equivalent S(5)Pr3As trigonal pyramids,  an edgeedge with one S(1)Pr4 tetrahedra, edges with two equivalent S(2)Pr4 tetrahedra,  an edgeedge with one S(4)Pr3As trigonal pyramid, and  an edgeedge with one S(5)Pr3As trigonal pyramid. In the third S site, S(3) is bonded in a distorted see-saw-like geometry to one Pr(3), two equivalent Pr(2), and one As(1) atom. In the fourth S site, S(4) is bonded to one Pr(2), two equivalent Pr(3), and one As(1) atom to form SPr3As trigonal pyramids that share corners with two equivalent S(1)Pr4 tetrahedra, corners with two equivalent S(2)Pr4 tetrahedra, corners with two equivalent S(4)Pr3As trigonal pyramids, corners with three equivalent S(5)Pr3As trigonal pyramids,  an edgeedge with one S(2)Pr4 tetrahedra, and  an edgeedge with one S(5)Pr3As trigonal pyramid. In the fifth S site, S(5) is bonded to one Pr(1), two equivalent Pr(3), and one As(1) atom to form distorted SPr3As trigonal pyramids that share corners with two equivalent S(1)Pr4 tetrahedra, corners with four equivalent S(2)Pr4 tetrahedra, corners with two equivalent S(5)Pr3As trigonal pyramids, corners with three equivalent S(4)Pr3As trigonal pyramids,  an edgeedge with one S(2)Pr4 tetrahedra, and  an edgeedge with one S(4)Pr3As trigonal pyramid. There are two inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a 3-coordinate geometry to one Pr(1) and two equivalent Pr(2) atoms. In the second Cl site, Cl(2) is bonded in a 3-coordinate geometry to one Pr(2) and two equivalent Pr(1) atoms.