Rb2Na2MgTi2O6 crystallizes in the triclinic P1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 4-coordinate geometry to one O(2), one O(6), and two equivalent O(3) atoms. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to one Mg(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(4), and one O(5) atom. Mg(1) is bonded in a distorted trigonal non-coplanar geometry to one Rb(2), one O(3), one O(4), and one O(6) atom. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form distorted edge-sharing TiO5 trigonal bipyramids. In the second Ti site, Ti(2) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(6) atom to form distorted edge-sharing TiO5 trigonal bipyramids. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Na(1), one Na(2), one Ti(1), and one Ti(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Rb(1), one Rb(2), one Na(1), one Ti(1), and one Ti(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Rb(2), two equivalent Rb(1), one Na(2), one Mg(1), and one Ti(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Rb(2), one Na(1), one Na(2), one Mg(1), one Ti(1), and one Ti(2) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Rb(2), one Na(1), one Na(2), one Ti(1), and one Ti(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Na(1), one Mg(1), and one Ti(2) atom.
Rb2Na2MgTi2O6 crystallizes in the triclinic P1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 4-coordinate geometry to one O(2), one O(6), and two equivalent O(3) atoms. The Rb(1)-O(2) bond length is 2.88 Å. The Rb(1)-O(6) bond length is 2.93 Å. There is one shorter (2.82 Å) and one longer (2.96 Å) Rb(1)-O(3) bond length. In the second Rb site, Rb(2) is bonded in a 6-coordinate geometry to one Mg(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Rb(2)-Mg(1) bond length is 2.97 Å. The Rb(2)-O(2) bond length is 2.70 Å. The Rb(2)-O(3) bond length is 2.87 Å. The Rb(2)-O(4) bond length is 2.88 Å. The Rb(2)-O(5) bond length is 2.81 Å. The Rb(2)-O(6) bond length is 3.15 Å. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(4), one O(5), and one O(6) atom. The Na(1)-O(1) bond length is 2.21 Å. The Na(1)-O(2) bond length is 2.33 Å. The Na(1)-O(4) bond length is 2.80 Å. The Na(1)-O(5) bond length is 2.50 Å. The Na(1)-O(6) bond length is 2.59 Å. In the second Na site, Na(2) is bonded in a 4-coordinate geometry to one O(1), one O(3), one O(4), and one O(5) atom. The Na(2)-O(1) bond length is 2.32 Å. The Na(2)-O(3) bond length is 2.55 Å. The Na(2)-O(4) bond length is 2.52 Å. The Na(2)-O(5) bond length is 2.27 Å. Mg(1) is bonded in a distorted trigonal non-coplanar geometry to one Rb(2), one O(3), one O(4), and one O(6) atom. The Mg(1)-O(3) bond length is 2.00 Å. The Mg(1)-O(4) bond length is 2.00 Å. The Mg(1)-O(6) bond length is 2.02 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(2), one O(3), one O(4), and one O(5) atom to form distorted edge-sharing TiO5 trigonal bipyramids. The Ti(1)-O(1) bond length is 1.89 Å. The Ti(1)-O(2) bond length is 2.10 Å. The Ti(1)-O(3) bond length is 1.98 Å. The Ti(1)-O(4) bond length is 2.06 Å. The Ti(1)-O(5) bond length is 2.00 Å. In the second Ti site, Ti(2) is bonded to one O(1), one O(2), one O(4), one O(5), and one O(6) atom to form distorted edge-sharing TiO5 trigonal bipyramids. The Ti(2)-O(1) bond length is 2.11 Å. The Ti(2)-O(2) bond length is 1.91 Å. The Ti(2)-O(4) bond length is 2.23 Å. The Ti(2)-O(5) bond length is 1.95 Å. The Ti(2)-O(6) bond length is 1.90 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted see-saw-like geometry to one Na(1), one Na(2), one Ti(1), and one Ti(2) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Rb(1), one Rb(2), one Na(1), one Ti(1), and one Ti(2) atom. In the third O site, O(3) is bonded in a 6-coordinate geometry to one Rb(2), two equivalent Rb(1), one Na(2), one Mg(1), and one Ti(1) atom. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Rb(2), one Na(1), one Na(2), one Mg(1), one Ti(1), and one Ti(2) atom. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Rb(2), one Na(1), one Na(2), one Ti(1), and one Ti(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Rb(1), one Rb(2), one Na(1), one Mg(1), and one Ti(2) atom.