Na4Dy2(IrO4)3 crystallizes in the hexagonal P-62m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(3), and four equivalent O(1) atoms. In the second Na site, Na(2) is bonded to six equivalent O(3) atoms to form distorted NaO6 pentagonal pyramids that share corners with six equivalent Ir(1)O6 octahedra, edges with three equivalent Ir(1)O6 octahedra, and faces with two equivalent Na(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 11°. Dy(1) is bonded in a 9-coordinate geometry to three equivalent O(2) and six equivalent O(1) atoms. Ir(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form IrO6 octahedra that share corners with two equivalent Na(2)O6 pentagonal pyramids, edges with two equivalent Ir(1)O6 octahedra, and  an edgeedge with one Na(2)O6 pentagonal pyramid. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), two equivalent Dy(1), and one Ir(1) atom to form distorted ONa2Dy2Ir trigonal bipyramids that share corners with two equivalent O(3)Na4Ir2 octahedra, corners with seven equivalent O(1)Na2Dy2Ir trigonal bipyramids, edges with two equivalent O(3)Na4Ir2 octahedra, and edges with five equivalent O(1)Na2Dy2Ir trigonal bipyramids. The corner-sharing octahedral tilt angles are 52°. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Dy(1), and two equivalent Ir(1) atoms. In the third O site, O(3) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Ir(1) atoms to form ONa4Ir2 octahedra that share corners with four equivalent O(3)Na4Ir2 octahedra, corners with four equivalent O(1)Na2Dy2Ir trigonal bipyramids, edges with two equivalent O(3)Na4Ir2 octahedra, edges with four equivalent O(1)Na2Dy2Ir trigonal bipyramids, and faces with two equivalent O(3)Na4Ir2 octahedra. The corner-sharing octahedral tilt angles are 45°.
Na4Dy2(IrO4)3 crystallizes in the hexagonal P-62m space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 7-coordinate geometry to one O(2), two equivalent O(3), and four equivalent O(1) atoms. The Na(1)-O(2) bond length is 2.29 Å. Both Na(1)-O(3) bond lengths are 2.50 Å. All Na(1)-O(1) bond lengths are 2.44 Å. In the second Na site, Na(2) is bonded to six equivalent O(3) atoms to form distorted NaO6 pentagonal pyramids that share corners with six equivalent Ir(1)O6 octahedra, edges with three equivalent Ir(1)O6 octahedra, and faces with two equivalent Na(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 11°. All Na(2)-O(3) bond lengths are 2.45 Å. Dy(1) is bonded in a 9-coordinate geometry to three equivalent O(2) and six equivalent O(1) atoms. All Dy(1)-O(2) bond lengths are 2.76 Å. All Dy(1)-O(1) bond lengths are 2.33 Å. Ir(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form IrO6 octahedra that share corners with two equivalent Na(2)O6 pentagonal pyramids, edges with two equivalent Ir(1)O6 octahedra, and  an edgeedge with one Na(2)O6 pentagonal pyramid. Both Ir(1)-O(1) bond lengths are 2.00 Å. Both Ir(1)-O(2) bond lengths are 2.00 Å. Both Ir(1)-O(3) bond lengths are 2.04 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), two equivalent Dy(1), and one Ir(1) atom to form distorted ONa2Dy2Ir trigonal bipyramids that share corners with two equivalent O(3)Na4Ir2 octahedra, corners with seven equivalent O(1)Na2Dy2Ir trigonal bipyramids, edges with two equivalent O(3)Na4Ir2 octahedra, and edges with five equivalent O(1)Na2Dy2Ir trigonal bipyramids. The corner-sharing octahedral tilt angles are 52°. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Na(1), two equivalent Dy(1), and two equivalent Ir(1) atoms. In the third O site, O(3) is bonded to two equivalent Na(1), two equivalent Na(2), and two equivalent Ir(1) atoms to form ONa4Ir2 octahedra that share corners with four equivalent O(3)Na4Ir2 octahedra, corners with four equivalent O(1)Na2Dy2Ir trigonal bipyramids, edges with two equivalent O(3)Na4Ir2 octahedra, edges with four equivalent O(1)Na2Dy2Ir trigonal bipyramids, and faces with two equivalent O(3)Na4Ir2 octahedra. The corner-sharing octahedral tilt angles are 45°.