Rb8Mg(FeO4)2 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the triclinic P1 space group. There are eight inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(6), and one O(8) atom. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(7) atom. In the third Rb site, Rb(3) is bonded in a 3-coordinate geometry to one O(1), one O(6), and one O(7) atom. In the fourth Rb site, Rb(4) is bonded in a 4-coordinate geometry to one O(2), one O(6), one O(7), and one O(8) atom. In the fifth Rb site, Rb(5) is bonded in a 4-coordinate geometry to one O(3), one O(4), one O(5), and one O(7) atom. In the sixth Rb site, Rb(6) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(6), and one O(8) atom. In the seventh Rb site, Rb(7) is bonded in a 4-coordinate geometry to one O(4), one O(6), one O(7), and one O(8) atom. In the eighth Rb site, Rb(8) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(6), and one O(8) atom. Mg(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form distorted MgO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra and corners with three equivalent Fe(1)O4 tetrahedra. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form FeO4 tetrahedra that share corners with three equivalent Mg(1)O4 tetrahedra. In the second Fe site, Fe(2) is bonded to one O(4), one O(6), one O(7), and one O(8) atom to form FeO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Rb(1), one Rb(3), one Rb(6), one Rb(8), and one Fe(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Rb(2), one Rb(4), one Rb(6), one Mg(1), and one Fe(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Rb(1), one Rb(2), one Rb(5), one Rb(8), one Mg(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Rb(2), one Rb(5), one Rb(7), one Mg(1), and one Fe(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Rb(5), one Mg(1), and one Fe(1) atom. In the sixth O site, O(6) is bonded in a 7-coordinate geometry to one Rb(1), one Rb(3), one Rb(4), one Rb(6), one Rb(7), one Rb(8), and one Fe(2) atom. In the seventh O site, O(7) is bonded in a distorted octahedral geometry to one Rb(2), one Rb(3), one Rb(4), one Rb(5), one Rb(7), and one Fe(2) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(4), one Rb(6), one Rb(7), one Rb(8), and one Fe(2) atom.
Rb8Mg(FeO4)2 is Pb (Zr_0.50 Ti_0.48) O_3-derived structured and crystallizes in the triclinic P1 space group. There are eight inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(1), one O(3), one O(5), one O(6), and one O(8) atom. The Rb(1)-O(1) bond length is 2.78 Å. The Rb(1)-O(3) bond length is 2.95 Å. The Rb(1)-O(5) bond length is 3.37 Å. The Rb(1)-O(6) bond length is 2.81 Å. The Rb(1)-O(8) bond length is 2.96 Å. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), one O(5), and one O(7) atom. The Rb(2)-O(2) bond length is 2.98 Å. The Rb(2)-O(3) bond length is 2.74 Å. The Rb(2)-O(4) bond length is 2.66 Å. The Rb(2)-O(5) bond length is 3.09 Å. The Rb(2)-O(7) bond length is 2.87 Å. In the third Rb site, Rb(3) is bonded in a 3-coordinate geometry to one O(1), one O(6), and one O(7) atom. The Rb(3)-O(1) bond length is 2.63 Å. The Rb(3)-O(6) bond length is 3.02 Å. The Rb(3)-O(7) bond length is 2.69 Å. In the fourth Rb site, Rb(4) is bonded in a 4-coordinate geometry to one O(2), one O(6), one O(7), and one O(8) atom. The Rb(4)-O(2) bond length is 3.02 Å. The Rb(4)-O(6) bond length is 3.00 Å. The Rb(4)-O(7) bond length is 2.69 Å. The Rb(4)-O(8) bond length is 3.11 Å. In the fifth Rb site, Rb(5) is bonded in a 4-coordinate geometry to one O(3), one O(4), one O(5), and one O(7) atom. The Rb(5)-O(3) bond length is 2.63 Å. The Rb(5)-O(4) bond length is 2.80 Å. The Rb(5)-O(5) bond length is 2.83 Å. The Rb(5)-O(7) bond length is 2.80 Å. In the sixth Rb site, Rb(6) is bonded in a 4-coordinate geometry to one O(1), one O(2), one O(6), and one O(8) atom. The Rb(6)-O(1) bond length is 2.88 Å. The Rb(6)-O(2) bond length is 2.95 Å. The Rb(6)-O(6) bond length is 2.94 Å. The Rb(6)-O(8) bond length is 2.74 Å. In the seventh Rb site, Rb(7) is bonded in a 4-coordinate geometry to one O(4), one O(6), one O(7), and one O(8) atom. The Rb(7)-O(4) bond length is 2.75 Å. The Rb(7)-O(6) bond length is 2.83 Å. The Rb(7)-O(7) bond length is 2.70 Å. The Rb(7)-O(8) bond length is 2.74 Å. In the eighth Rb site, Rb(8) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(3), one O(6), and one O(8) atom. The Rb(8)-O(1) bond length is 2.75 Å. The Rb(8)-O(3) bond length is 2.98 Å. The Rb(8)-O(6) bond length is 3.17 Å. The Rb(8)-O(8) bond length is 2.78 Å. Mg(1) is bonded to one O(2), one O(3), one O(4), and one O(5) atom to form distorted MgO4 tetrahedra that share  a cornercorner with one Fe(2)O4 tetrahedra and corners with three equivalent Fe(1)O4 tetrahedra. The Mg(1)-O(2) bond length is 2.05 Å. The Mg(1)-O(3) bond length is 2.35 Å. The Mg(1)-O(4) bond length is 2.06 Å. The Mg(1)-O(5) bond length is 2.09 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form FeO4 tetrahedra that share corners with three equivalent Mg(1)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.85 Å. The Fe(1)-O(2) bond length is 2.02 Å. The Fe(1)-O(3) bond length is 2.02 Å. The Fe(1)-O(5) bond length is 2.05 Å. In the second Fe site, Fe(2) is bonded to one O(4), one O(6), one O(7), and one O(8) atom to form FeO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra. The Fe(2)-O(4) bond length is 1.99 Å. The Fe(2)-O(6) bond length is 1.93 Å. The Fe(2)-O(7) bond length is 1.91 Å. The Fe(2)-O(8) bond length is 1.92 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Rb(1), one Rb(3), one Rb(6), one Rb(8), and one Fe(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to one Rb(2), one Rb(4), one Rb(6), one Mg(1), and one Fe(1) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Rb(1), one Rb(2), one Rb(5), one Rb(8), one Mg(1), and one Fe(1) atom. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Rb(2), one Rb(5), one Rb(7), one Mg(1), and one Fe(2) atom. In the fifth O site, O(5) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Rb(5), one Mg(1), and one Fe(1) atom. In the sixth O site, O(6) is bonded in a 7-coordinate geometry to one Rb(1), one Rb(3), one Rb(4), one Rb(6), one Rb(7), one Rb(8), and one Fe(2) atom. In the seventh O site, O(7) is bonded in a distorted octahedral geometry to one Rb(2), one Rb(3), one Rb(4), one Rb(5), one Rb(7), and one Fe(2) atom. In the eighth O site, O(8) is bonded in a 1-coordinate geometry to one Rb(1), one Rb(4), one Rb(6), one Rb(7), one Rb(8), and one Fe(2) atom.