Rb2Mg(FeS2)2 crystallizes in the monoclinic C2 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent S(2), and four equivalent S(1) atoms. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to four equivalent S(1) and four equivalent S(2) atoms. Mg(1) is bonded in a 4-coordinate geometry to two equivalent Rb(1), two equivalent S(1), and two equivalent S(2) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form edge-sharing FeS4 tetrahedra. In the second Fe site, Fe(2) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form edge-sharing FeS4 tetrahedra. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Mg(1), one Fe(1), and one Fe(2) atom. In the second S site, S(2) is bonded in a 3-coordinate geometry to one Rb(1), two equivalent Rb(2), one Mg(1), one Fe(1), and one Fe(2) atom.
Rb2Mg(FeS2)2 crystallizes in the monoclinic C2 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 8-coordinate geometry to two equivalent Mg(1), two equivalent S(2), and four equivalent S(1) atoms. Both Rb(1)-Mg(1) bond lengths are 3.27 Å. Both Rb(1)-S(2) bond lengths are 3.18 Å. There are two shorter (3.29 Å) and two longer (3.47 Å) Rb(1)-S(1) bond lengths. In the second Rb site, Rb(2) is bonded in a 8-coordinate geometry to four equivalent S(1) and four equivalent S(2) atoms. There are two shorter (3.38 Å) and two longer (3.64 Å) Rb(2)-S(1) bond lengths. There are two shorter (3.40 Å) and two longer (3.61 Å) Rb(2)-S(2) bond lengths. Mg(1) is bonded in a 4-coordinate geometry to two equivalent Rb(1), two equivalent S(1), and two equivalent S(2) atoms. Both Mg(1)-S(1) bond lengths are 2.59 Å. Both Mg(1)-S(2) bond lengths are 2.43 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form edge-sharing FeS4 tetrahedra. Both Fe(1)-S(1) bond lengths are 2.20 Å. Both Fe(1)-S(2) bond lengths are 2.21 Å. In the second Fe site, Fe(2) is bonded to two equivalent S(1) and two equivalent S(2) atoms to form edge-sharing FeS4 tetrahedra. Both Fe(2)-S(1) bond lengths are 2.19 Å. Both Fe(2)-S(2) bond lengths are 2.19 Å. There are two inequivalent S sites. In the first S site, S(1) is bonded in a 7-coordinate geometry to two equivalent Rb(1), two equivalent Rb(2), one Mg(1), one Fe(1), and one Fe(2) atom. In the second S site, S(2) is bonded in a 3-coordinate geometry to one Rb(1), two equivalent Rb(2), one Mg(1), one Fe(1), and one Fe(2) atom.