K2S5 crystallizes in the orthorhombic P2_12_12_1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one S(1), two equivalent S(3), two equivalent S(5), and three equivalent S(4) atoms. In the second K site, K(2) is bonded in a 7-coordinate geometry to one S(5), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms. There are five inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one K(1), two equivalent K(2), and one S(2) atom. In the second S site, S(2) is bonded in a trigonal non-coplanar geometry to one S(1), one S(4), and one S(5) atom. In the third S site, S(3) is bonded to two equivalent K(1), two equivalent K(2), and one S(5) atom to form distorted SK4S square pyramids that share corners with two equivalent S(4)K5S octahedra, corners with four equivalent S(3)K4S square pyramids, and edges with four equivalent S(4)K5S octahedra. The corner-sharing octahedral tilt angles range from 24-83°. In the fourth S site, S(4) is bonded to two equivalent K(2), three equivalent K(1), and one S(2) atom to form distorted SK5S octahedra that share corners with four equivalent S(4)K5S octahedra, corners with two equivalent S(3)K4S square pyramids, edges with two equivalent S(4)K5S octahedra, and edges with four equivalent S(3)K4S square pyramids. The corner-sharing octahedral tilt angles range from 2-45°. In the fifth S site, S(5) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(1), one S(2), and one S(3) atom.
K2S5 crystallizes in the orthorhombic P2_12_12_1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to one S(1), two equivalent S(3), two equivalent S(5), and three equivalent S(4) atoms. The K(1)-S(1) bond length is 3.23 Å. There is one shorter (3.23 Å) and one longer (3.32 Å) K(1)-S(3) bond length. Both K(1)-S(5) bond lengths are 3.49 Å. There are a spread of K(1)-S(4) bond distances ranging from 3.24-3.58 Å. In the second K site, K(2) is bonded in a 7-coordinate geometry to one S(5), two equivalent S(1), two equivalent S(3), and two equivalent S(4) atoms. The K(2)-S(5) bond length is 3.48 Å. There is one shorter (3.33 Å) and one longer (3.36 Å) K(2)-S(1) bond length. There is one shorter (3.23 Å) and one longer (3.68 Å) K(2)-S(3) bond length. There is one shorter (3.42 Å) and one longer (3.44 Å) K(2)-S(4) bond length. There are five inequivalent S sites. In the first S site, S(1) is bonded in a rectangular see-saw-like geometry to one K(1), two equivalent K(2), and one S(2) atom. The S(1)-S(2) bond length is 2.02 Å. In the second S site, S(2) is bonded in a trigonal non-coplanar geometry to one S(1), one S(4), and one S(5) atom. The S(2)-S(4) bond length is 2.03 Å. The S(2)-S(5) bond length is 2.42 Å. In the third S site, S(3) is bonded to two equivalent K(1), two equivalent K(2), and one S(5) atom to form distorted SK4S square pyramids that share corners with two equivalent S(4)K5S octahedra, corners with four equivalent S(3)K4S square pyramids, and edges with four equivalent S(4)K5S octahedra. The corner-sharing octahedral tilt angles range from 24-83°. The S(3)-S(5) bond length is 2.02 Å. In the fourth S site, S(4) is bonded to two equivalent K(2), three equivalent K(1), and one S(2) atom to form distorted SK5S octahedra that share corners with four equivalent S(4)K5S octahedra, corners with two equivalent S(3)K4S square pyramids, edges with two equivalent S(4)K5S octahedra, and edges with four equivalent S(3)K4S square pyramids. The corner-sharing octahedral tilt angles range from 2-45°. In the fifth S site, S(5) is bonded in a 5-coordinate geometry to one K(2), two equivalent K(1), one S(2), and one S(3) atom.