K2Fe2SeS3 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Se(1), one S(1), one S(2), and one S(3) atom to form edge-sharing FeSeS3 tetrahedra. In the second Fe site, Fe(2) is bonded to one Se(1), one S(1), one S(2), and one S(3) atom to form edge-sharing FeSeS3 tetrahedra. Se(1) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(2), one Fe(1), and one Fe(2) atom. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(2), one Fe(1), and one Fe(2) atom. In the second S site, S(2) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(2), one Fe(1), and one Fe(2) atom. In the third S site, S(3) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(2), one Fe(1), and one Fe(2) atom.
K2Fe2SeS3 crystallizes in the triclinic P1 space group. There are two inequivalent K sites. In the first K site, K(1) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms. There is one shorter (3.39 Å) and one longer (3.48 Å) K(1)-Se(1) bond length. There is one shorter (3.40 Å) and one longer (3.45 Å) K(1)-S(1) bond length. There is one shorter (3.41 Å) and one longer (3.44 Å) K(1)-S(2) bond length. There is one shorter (3.42 Å) and one longer (3.45 Å) K(1)-S(3) bond length. In the second K site, K(2) is bonded in a 8-coordinate geometry to two equivalent Se(1), two equivalent S(1), two equivalent S(2), and two equivalent S(3) atoms. There is one shorter (3.38 Å) and one longer (3.44 Å) K(2)-Se(1) bond length. There is one shorter (3.36 Å) and one longer (3.40 Å) K(2)-S(1) bond length. There is one shorter (3.42 Å) and one longer (3.43 Å) K(2)-S(2) bond length. There is one shorter (3.35 Å) and one longer (3.53 Å) K(2)-S(3) bond length. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one Se(1), one S(1), one S(2), and one S(3) atom to form edge-sharing FeSeS3 tetrahedra. The Fe(1)-Se(1) bond length is 2.35 Å. The Fe(1)-S(1) bond length is 2.19 Å. The Fe(1)-S(2) bond length is 2.18 Å. The Fe(1)-S(3) bond length is 2.18 Å. In the second Fe site, Fe(2) is bonded to one Se(1), one S(1), one S(2), and one S(3) atom to form edge-sharing FeSeS3 tetrahedra. The Fe(2)-Se(1) bond length is 2.33 Å. The Fe(2)-S(1) bond length is 2.18 Å. The Fe(2)-S(2) bond length is 2.19 Å. The Fe(2)-S(3) bond length is 2.19 Å. Se(1) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(2), one Fe(1), and one Fe(2) atom. There are three inequivalent S sites. In the first S site, S(1) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(2), one Fe(1), and one Fe(2) atom. In the second S site, S(2) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(2), one Fe(1), and one Fe(2) atom. In the third S site, S(3) is bonded in a 6-coordinate geometry to two equivalent K(1), two equivalent K(2), one Fe(1), and one Fe(2) atom.