Rb2MgPr2(WO4)4 crystallizes in the monoclinic C2 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(6), and two equivalent O(8) atoms. In the second Rb site, Rb(2) is bonded in a 11-coordinate geometry to one Mg(1), two equivalent O(1), two equivalent O(2), two equivalent O(4), two equivalent O(5), and two equivalent O(7) atoms. Mg(1) is bonded in a 4-coordinate geometry to one Rb(2), two equivalent O(1), two equivalent O(7), and two equivalent O(8) atoms. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), two equivalent O(5), and two equivalent O(7) atoms. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), two equivalent O(6), and two equivalent O(8) atoms. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form a mixture of edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 39-42°. In the second W site, W(2) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(8) atom to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 39-42°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1), one Rb(2), one Mg(1), one W(1), and one W(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one W(1), and one W(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Rb(1), one Pr(1), one Pr(2), and one W(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Rb(2), one Pr(1), one Pr(2), and one W(2) atom. In the fifth O site, O(5) is bonded to one Rb(2), one Pr(1), one W(1), and one W(2) atom to form a mixture of distorted edge and corner-sharing ORbPrW2 trigonal pyramids. In the sixth O site, O(6) is bonded to one Rb(1), one Pr(2), one W(1), and one W(2) atom to form a mixture of distorted edge and corner-sharing ORbPrW2 tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Rb(2), one Mg(1), one Pr(1), and one W(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Rb(1), one Mg(1), one Pr(2), and one W(2) atom.
Rb2MgPr2(WO4)4 crystallizes in the monoclinic C2 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 10-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(6), and two equivalent O(8) atoms. Both Rb(1)-O(1) bond lengths are 3.22 Å. Both Rb(1)-O(2) bond lengths are 3.07 Å. Both Rb(1)-O(3) bond lengths are 3.18 Å. Both Rb(1)-O(6) bond lengths are 2.94 Å. Both Rb(1)-O(8) bond lengths are 2.97 Å. In the second Rb site, Rb(2) is bonded in a 11-coordinate geometry to one Mg(1), two equivalent O(1), two equivalent O(2), two equivalent O(4), two equivalent O(5), and two equivalent O(7) atoms. The Rb(2)-Mg(1) bond length is 2.90 Å. Both Rb(2)-O(1) bond lengths are 3.12 Å. Both Rb(2)-O(2) bond lengths are 2.70 Å. Both Rb(2)-O(4) bond lengths are 3.38 Å. Both Rb(2)-O(5) bond lengths are 2.83 Å. Both Rb(2)-O(7) bond lengths are 3.20 Å. Mg(1) is bonded in a 4-coordinate geometry to one Rb(2), two equivalent O(1), two equivalent O(7), and two equivalent O(8) atoms. Both Mg(1)-O(1) bond lengths are 2.18 Å. Both Mg(1)-O(7) bond lengths are 2.62 Å. Both Mg(1)-O(8) bond lengths are 2.03 Å. There are two inequivalent Pr sites. In the first Pr site, Pr(1) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), two equivalent O(5), and two equivalent O(7) atoms. Both Pr(1)-O(3) bond lengths are 2.81 Å. Both Pr(1)-O(4) bond lengths are 2.42 Å. Both Pr(1)-O(5) bond lengths are 2.45 Å. Both Pr(1)-O(7) bond lengths are 2.48 Å. In the second Pr site, Pr(2) is bonded in a 8-coordinate geometry to two equivalent O(3), two equivalent O(4), two equivalent O(6), and two equivalent O(8) atoms. Both Pr(2)-O(3) bond lengths are 2.50 Å. Both Pr(2)-O(4) bond lengths are 2.64 Å. Both Pr(2)-O(6) bond lengths are 2.39 Å. Both Pr(2)-O(8) bond lengths are 2.49 Å. There are two inequivalent W sites. In the first W site, W(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form a mixture of edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 39-42°. The W(1)-O(1) bond length is 2.07 Å. The W(1)-O(2) bond length is 1.92 Å. The W(1)-O(3) bond length is 1.89 Å. The W(1)-O(5) bond length is 2.16 Å. The W(1)-O(6) bond length is 1.96 Å. The W(1)-O(7) bond length is 1.86 Å. In the second W site, W(2) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(8) atom to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 39-42°. The W(2)-O(1) bond length is 2.04 Å. The W(2)-O(2) bond length is 2.08 Å. The W(2)-O(4) bond length is 1.90 Å. The W(2)-O(5) bond length is 2.01 Å. The W(2)-O(6) bond length is 2.20 Å. The W(2)-O(8) bond length is 1.94 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Rb(1), one Rb(2), one Mg(1), one W(1), and one W(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one W(1), and one W(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Rb(1), one Pr(1), one Pr(2), and one W(1) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Rb(2), one Pr(1), one Pr(2), and one W(2) atom. In the fifth O site, O(5) is bonded to one Rb(2), one Pr(1), one W(1), and one W(2) atom to form a mixture of distorted edge and corner-sharing ORbPrW2 trigonal pyramids. In the sixth O site, O(6) is bonded to one Rb(1), one Pr(2), one W(1), and one W(2) atom to form a mixture of distorted edge and corner-sharing ORbPrW2 tetrahedra. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Rb(2), one Mg(1), one Pr(1), and one W(1) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Rb(1), one Mg(1), one Pr(2), and one W(2) atom.