Rb2Na2IrO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(4) atoms. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(1) atoms. In the second Na site, Na(2) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form edge-sharing NaO5 trigonal bipyramids. Ir(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Rb(1), two equivalent Na(1), two equivalent Na(2), and one Ir(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Rb(1), two equivalent Rb(2), one Na(1), one Na(2), and one Ir(1) atom. In the third O site, O(3) is bonded to one Rb(1), two equivalent Rb(2), one Na(1), one Na(2), and one Ir(1) atom to form distorted corner-sharing ORb3Na2Ir octahedra. The corner-sharing octahedral tilt angles are 57°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Rb(2), two equivalent Rb(1), one Na(1), one Na(2), and one Ir(1) atom.
Rb2Na2IrO4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), and two equivalent O(4) atoms. The Rb(1)-O(1) bond length is 3.04 Å. The Rb(1)-O(2) bond length is 3.01 Å. The Rb(1)-O(3) bond length is 2.83 Å. There is one shorter (2.85 Å) and one longer (2.92 Å) Rb(1)-O(4) bond length. In the second Rb site, Rb(2) is bonded in a 5-coordinate geometry to one O(4), two equivalent O(2), and two equivalent O(3) atoms. The Rb(2)-O(4) bond length is 2.85 Å. There is one shorter (2.83 Å) and one longer (2.98 Å) Rb(2)-O(2) bond length. There is one shorter (2.77 Å) and one longer (2.84 Å) Rb(2)-O(3) bond length. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 5-coordinate geometry to one O(2), one O(3), one O(4), and two equivalent O(1) atoms. The Na(1)-O(2) bond length is 2.34 Å. The Na(1)-O(3) bond length is 2.32 Å. The Na(1)-O(4) bond length is 2.40 Å. There is one shorter (2.38 Å) and one longer (2.41 Å) Na(1)-O(1) bond length. In the second Na site, Na(2) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form edge-sharing NaO5 trigonal bipyramids. The Na(2)-O(2) bond length is 2.38 Å. The Na(2)-O(3) bond length is 2.31 Å. The Na(2)-O(4) bond length is 2.35 Å. There is one shorter (2.35 Å) and one longer (2.38 Å) Na(2)-O(1) bond length. Ir(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(4) atom. The Ir(1)-O(1) bond length is 1.94 Å. The Ir(1)-O(2) bond length is 1.92 Å. The Ir(1)-O(3) bond length is 1.92 Å. The Ir(1)-O(4) bond length is 1.92 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Rb(1), two equivalent Na(1), two equivalent Na(2), and one Ir(1) atom. In the second O site, O(2) is bonded in a 6-coordinate geometry to one Rb(1), two equivalent Rb(2), one Na(1), one Na(2), and one Ir(1) atom. In the third O site, O(3) is bonded to one Rb(1), two equivalent Rb(2), one Na(1), one Na(2), and one Ir(1) atom to form distorted corner-sharing ORb3Na2Ir octahedra. The corner-sharing octahedral tilt angles are 57°. In the fourth O site, O(4) is bonded in a 6-coordinate geometry to one Rb(2), two equivalent Rb(1), one Na(1), one Na(2), and one Ir(1) atom.