RbK(Fe2S3)2 crystallizes in the orthorhombic Amm2 space group. Rb(1) is bonded in a 10-coordinate geometry to two equivalent S(4), four equivalent S(1), and four equivalent S(2) atoms. K(1) is bonded in a 10-coordinate geometry to two equivalent S(3), four equivalent S(1), and four equivalent S(2) atoms. Fe(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form a mixture of corner and edge-sharing FeS4 tetrahedra. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent K(1), and two equivalent Fe(1) atoms. In the second S site, S(2) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent K(1), and two equivalent Fe(1) atoms. In the third S site, S(3) is bonded in a 4-coordinate geometry to two equivalent K(1) and four equivalent Fe(1) atoms. In the fourth S site, S(4) is bonded in a 4-coordinate geometry to two equivalent Rb(1) and four equivalent Fe(1) atoms.
RbK(Fe2S3)2 crystallizes in the orthorhombic Amm2 space group. Rb(1) is bonded in a 10-coordinate geometry to two equivalent S(4), four equivalent S(1), and four equivalent S(2) atoms. Both Rb(1)-S(4) bond lengths are 3.59 Å. There are two shorter (3.52 Å) and two longer (3.71 Å) Rb(1)-S(1) bond lengths. All Rb(1)-S(2) bond lengths are 3.37 Å. K(1) is bonded in a 10-coordinate geometry to two equivalent S(3), four equivalent S(1), and four equivalent S(2) atoms. Both K(1)-S(3) bond lengths are 3.59 Å. All K(1)-S(1) bond lengths are 3.36 Å. There are two shorter (3.50 Å) and two longer (3.73 Å) K(1)-S(2) bond lengths. Fe(1) is bonded to one S(1), one S(2), one S(3), and one S(4) atom to form a mixture of corner and edge-sharing FeS4 tetrahedra. The Fe(1)-S(1) bond length is 2.13 Å. The Fe(1)-S(2) bond length is 2.13 Å. The Fe(1)-S(3) bond length is 2.19 Å. The Fe(1)-S(4) bond length is 2.19 Å. There are four inequivalent S sites. In the first S site, S(1) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent K(1), and two equivalent Fe(1) atoms. In the second S site, S(2) is bonded in a 2-coordinate geometry to two equivalent Rb(1), two equivalent K(1), and two equivalent Fe(1) atoms. In the third S site, S(3) is bonded in a 4-coordinate geometry to two equivalent K(1) and four equivalent Fe(1) atoms. In the fourth S site, S(4) is bonded in a 4-coordinate geometry to two equivalent Rb(1) and four equivalent Fe(1) atoms.