Rb2MgNb2(TeO6)2 crystallizes in the triclinic P1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 11-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(2), one O(3), one O(4), one O(6), one O(7), one O(8), and one O(9) atom. In the second Rb site, Rb(2) is bonded in a 3-coordinate geometry to one O(1), one O(3), and one O(6) atom. Mg(1) is bonded in a 4-coordinate geometry to one O(12), one O(5), one O(7), and one O(9) atom. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(11), one O(2), one O(4), one O(5), and one O(8) atom to form distorted NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra and corners with two equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-36°. In the second Nb site, Nb(2) is bonded to one O(12), one O(2), one O(3), one O(6), one O(8), and one O(9) atom to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-37°. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to one O(1), one O(10), one O(12), one O(4), one O(6), and one O(7) atom to form TeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-37°. In the second Te site, Te(2) is bonded in a 3-coordinate geometry to one O(1), one O(11), and one O(3) atom. There are twelve 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 Te(1), and one Te(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Nb(1), and one Nb(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one Nb(2), and one Te(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Nb(1), and one Te(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one Nb(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Nb(2), and one Te(1) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Rb(1), one Mg(1), and one Te(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Rb(1), one Nb(1), and one Nb(2) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one Rb(1), one Mg(1), and one Nb(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Nb(1), and one Te(1) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Rb(1), one Nb(1), and one Te(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Rb(1), one Mg(1), one Nb(2), and one Te(1) atom.
Rb2MgNb2(TeO6)2 crystallizes in the triclinic P1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 11-coordinate geometry to one O(1), one O(10), one O(11), one O(12), one O(2), one O(3), one O(4), one O(6), one O(7), one O(8), and one O(9) atom. The Rb(1)-O(1) bond length is 3.35 Å. The Rb(1)-O(10) bond length is 3.51 Å. The Rb(1)-O(11) bond length is 2.99 Å. The Rb(1)-O(12) bond length is 3.21 Å. The Rb(1)-O(2) bond length is 3.18 Å. The Rb(1)-O(3) bond length is 3.21 Å. The Rb(1)-O(4) bond length is 3.18 Å. The Rb(1)-O(6) bond length is 3.48 Å. The Rb(1)-O(7) bond length is 3.23 Å. The Rb(1)-O(8) bond length is 3.44 Å. The Rb(1)-O(9) bond length is 3.06 Å. In the second Rb site, Rb(2) is bonded in a 3-coordinate geometry to one O(1), one O(3), and one O(6) atom. The Rb(2)-O(1) bond length is 2.87 Å. The Rb(2)-O(3) bond length is 2.79 Å. The Rb(2)-O(6) bond length is 2.81 Å. Mg(1) is bonded in a 4-coordinate geometry to one O(12), one O(5), one O(7), and one O(9) atom. The Mg(1)-O(12) bond length is 2.30 Å. The Mg(1)-O(5) bond length is 1.92 Å. The Mg(1)-O(7) bond length is 1.94 Å. The Mg(1)-O(9) bond length is 1.95 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(11), one O(2), one O(4), one O(5), and one O(8) atom to form distorted NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra and corners with two equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-36°. The Nb(1)-O(10) bond length is 2.05 Å. The Nb(1)-O(11) bond length is 2.30 Å. The Nb(1)-O(2) bond length is 1.94 Å. The Nb(1)-O(4) bond length is 2.03 Å. The Nb(1)-O(5) bond length is 1.85 Å. The Nb(1)-O(8) bond length is 2.09 Å. In the second Nb site, Nb(2) is bonded to one O(12), one O(2), one O(3), one O(6), one O(8), and one O(9) atom to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-37°. The Nb(2)-O(12) bond length is 2.16 Å. The Nb(2)-O(2) bond length is 2.06 Å. The Nb(2)-O(3) bond length is 2.26 Å. The Nb(2)-O(6) bond length is 1.96 Å. The Nb(2)-O(8) bond length is 1.92 Å. The Nb(2)-O(9) bond length is 1.88 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to one O(1), one O(10), one O(12), one O(4), one O(6), and one O(7) atom to form TeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 33-37°. The Te(1)-O(1) bond length is 2.03 Å. The Te(1)-O(10) bond length is 1.96 Å. The Te(1)-O(12) bond length is 1.98 Å. The Te(1)-O(4) bond length is 1.96 Å. The Te(1)-O(6) bond length is 1.94 Å. The Te(1)-O(7) bond length is 1.90 Å. In the second Te site, Te(2) is bonded in a 3-coordinate geometry to one O(1), one O(11), and one O(3) atom. The Te(2)-O(1) bond length is 2.00 Å. The Te(2)-O(11) bond length is 1.86 Å. The Te(2)-O(3) bond length is 1.88 Å. There are twelve 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 Te(1), and one Te(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Nb(1), and one Nb(2) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Rb(1), one Rb(2), one Nb(2), and one Te(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Nb(1), and one Te(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one Nb(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Nb(2), and one Te(1) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Rb(1), one Mg(1), and one Te(1) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Rb(1), one Nb(1), and one Nb(2) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one Rb(1), one Mg(1), and one Nb(2) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Nb(1), and one Te(1) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Rb(1), one Nb(1), and one Te(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Rb(1), one Mg(1), one Nb(2), and one Te(1) atom.