Rb2MgNb2(TeO6)2 crystallizes in the monoclinic C2/m space group. Rb(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(4) atoms. Mg(1) is bonded in a distorted square co-planar geometry to four equivalent O(3) atoms. Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Te(1)O6 octahedra, and corners with two equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-66°. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form TeO6 octahedra that share corners with two equivalent Te(2)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-46°. In the second Te site, Te(2) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form TeO6 octahedra that share corners with two equivalent Te(1)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-66°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Rb(1), one Te(1), and one Te(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Rb(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Nb(1), and one Te(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Rb(1), one Nb(1), and one Te(1) atom.
Rb2MgNb2(TeO6)2 crystallizes in the monoclinic C2/m space group. Rb(1) is bonded in a 4-coordinate geometry to one O(1), one O(2), and two equivalent O(4) atoms. The Rb(1)-O(1) bond length is 2.85 Å. The Rb(1)-O(2) bond length is 2.71 Å. Both Rb(1)-O(4) bond lengths are 2.93 Å. Mg(1) is bonded in a distorted square co-planar geometry to four equivalent O(3) atoms. All Mg(1)-O(3) bond lengths are 2.08 Å. Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Te(1)O6 octahedra, and corners with two equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-66°. Both Nb(1)-O(2) bond lengths are 1.93 Å. Both Nb(1)-O(3) bond lengths are 2.03 Å. Both Nb(1)-O(4) bond lengths are 2.05 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(1) and four equivalent O(4) atoms to form TeO6 octahedra that share corners with two equivalent Te(2)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-46°. Both Te(1)-O(1) bond lengths are 1.97 Å. All Te(1)-O(4) bond lengths are 1.95 Å. In the second Te site, Te(2) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form TeO6 octahedra that share corners with two equivalent Te(1)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-66°. Both Te(2)-O(1) bond lengths are 2.12 Å. All Te(2)-O(3) bond lengths are 2.37 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Rb(1), one Te(1), and one Te(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Rb(1) and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1), one Nb(1), and one Te(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Rb(1), one Nb(1), and one Te(1) atom.