Rb2MgNd2(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 9-coordinate geometry to one Mg(1), two equivalent O(2), two equivalent O(3), two equivalent O(7), and two equivalent O(8) atoms. In the second Rb site, Rb(2) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms. Mg(1) is bonded in a distorted see-saw-like geometry to one Rb(1), two equivalent O(1), and two equivalent O(5) atoms. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms. In the second Nd site, Nd(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(7) 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(8) atom to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 35-41°. In the second W site, W(2) is bonded to one O(1), one O(4), one O(5), one O(6), one O(7), 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 35-41°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nd(2), 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 Nd(1), and one W(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Rb(1), one Nd(2), and one W(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Rb(2), one Nd(1), and one W(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Rb(2), one Mg(1), one W(1), and one W(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Rb(2), one Nd(1), one W(1), and one W(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Rb(1), one Nd(2), and one W(2) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one W(1), and one W(2) atom.
Rb2MgNd2(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 9-coordinate geometry to one Mg(1), two equivalent O(2), two equivalent O(3), two equivalent O(7), and two equivalent O(8) atoms. The Rb(1)-Mg(1) bond length is 2.89 Å. Both Rb(1)-O(2) bond lengths are 2.91 Å. Both Rb(1)-O(3) bond lengths are 3.09 Å. Both Rb(1)-O(7) bond lengths are 2.71 Å. Both Rb(1)-O(8) bond lengths are 2.83 Å. In the second Rb site, Rb(2) is bonded in a 10-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms. Both Rb(2)-O(2) bond lengths are 3.02 Å. Both Rb(2)-O(4) bond lengths are 3.11 Å. Both Rb(2)-O(5) bond lengths are 3.02 Å. Both Rb(2)-O(6) bond lengths are 3.15 Å. Both Rb(2)-O(8) bond lengths are 3.08 Å. Mg(1) is bonded in a distorted see-saw-like geometry to one Rb(1), two equivalent O(1), and two equivalent O(5) atoms. Both Mg(1)-O(1) bond lengths are 2.05 Å. Both Mg(1)-O(5) bond lengths are 1.92 Å. There are two inequivalent Nd sites. In the first Nd site, Nd(1) is bonded in a 6-coordinate geometry to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms. Both Nd(1)-O(2) bond lengths are 2.36 Å. Both Nd(1)-O(4) bond lengths are 2.46 Å. Both Nd(1)-O(6) bond lengths are 2.43 Å. In the second Nd site, Nd(2) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(3), and two equivalent O(7) atoms. Both Nd(2)-O(1) bond lengths are 2.47 Å. Both Nd(2)-O(3) bond lengths are 2.45 Å. Both Nd(2)-O(7) bond lengths are 2.39 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(8) atom to form a mixture of distorted edge and corner-sharing WO6 octahedra. The corner-sharing octahedral tilt angles range from 35-41°. The W(1)-O(1) bond length is 2.18 Å. The W(1)-O(2) bond length is 1.88 Å. The W(1)-O(3) bond length is 1.88 Å. The W(1)-O(5) bond length is 2.07 Å. The W(1)-O(6) bond length is 2.16 Å. The W(1)-O(8) bond length is 2.07 Å. In the second W site, W(2) is bonded to one O(1), one O(4), one O(5), one O(6), one O(7), 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 35-41°. The W(2)-O(1) bond length is 2.20 Å. The W(2)-O(4) bond length is 1.86 Å. The W(2)-O(5) bond length is 2.06 Å. The W(2)-O(6) bond length is 2.01 Å. The W(2)-O(7) bond length is 1.84 Å. The W(2)-O(8) bond length is 1.91 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one Nd(2), 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 Nd(1), and one W(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Rb(1), one Nd(2), and one W(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Rb(2), one Nd(1), and one W(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Rb(2), one Mg(1), one W(1), and one W(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Rb(2), one Nd(1), one W(1), and one W(2) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Rb(1), one Nd(2), and one W(2) atom. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one W(1), and one W(2) atom.