NaDy3Ti2(SbO7)2 crystallizes in the monoclinic P2/c space group. Na(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. There are three inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. In the second Dy site, Dy(2) is bonded to two equivalent O(1), two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form distorted DyO8 hexagonal bipyramids that share edges with two equivalent Dy(3)O8 hexagonal bipyramids, edges with two equivalent Ti(2)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and edges with two equivalent Sb(2)O6 octahedra. In the third Dy site, Dy(3) is bonded to two equivalent O(1), two equivalent O(3), two equivalent O(5), and two equivalent O(7) atoms to form distorted DyO8 hexagonal bipyramids that share edges with two equivalent Dy(2)O8 hexagonal bipyramids, edges with two equivalent Ti(1)O6 octahedra, edges with two equivalent Ti(2)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form TiO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, and edges with two equivalent Dy(3)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-46°. In the second Ti site, Ti(2) is bonded to two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, edges with two equivalent Dy(2)O8 hexagonal bipyramids, and edges with two equivalent Dy(3)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-48°. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(7) atoms to form SbO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, edges with two equivalent Dy(2)O8 hexagonal bipyramids, and edges with two equivalent Dy(3)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-49°. In the second Sb site, Sb(2) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form SbO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, and edges with two equivalent Dy(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-49°. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Dy(1), one Dy(2), and one Dy(3) atom to form ONaDy3 tetrahedra that share corners with two equivalent O(7)Dy2TiSb tetrahedra, corners with two equivalent O(4)NaDySb2 tetrahedra, corners with four equivalent O(1)NaDy3 tetrahedra, corners with two equivalent O(2)NaDyTiSb trigonal pyramids,  an edgeedge with one O(7)Dy2TiSb tetrahedra,  an edgeedge with one O(4)NaDySb2 tetrahedra, and  an edgeedge with one O(2)NaDyTiSb trigonal pyramid. In the second O site, O(2) is bonded to one Na(1), one Dy(1), one Ti(1), and one Sb(2) atom to form distorted ONaDyTiSb trigonal pyramids that share corners with two equivalent O(1)NaDy3 tetrahedra, corners with two equivalent O(4)NaDySb2 tetrahedra, corners with two equivalent O(2)NaDyTiSb trigonal pyramids,  an edgeedge with one O(1)NaDy3 tetrahedra,  an edgeedge with one O(4)NaDySb2 tetrahedra, and  an edgeedge with one O(2)NaDyTiSb trigonal pyramid. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), one Dy(3), one Ti(1), and one Sb(1) atom. In the fourth O site, O(4) is bonded to one Na(1), one Dy(2), one Sb(1), and one Sb(2) atom to form distorted ONaDySb2 tetrahedra that share corners with two equivalent O(1)NaDy3 tetrahedra, corners with two equivalent O(4)NaDySb2 tetrahedra, corners with four equivalent O(7)Dy2TiSb tetrahedra, corners with two equivalent O(2)NaDyTiSb trigonal pyramids,  an edgeedge with one O(1)NaDy3 tetrahedra,  an edgeedge with one O(4)NaDySb2 tetrahedra, and  an edgeedge with one O(2)NaDyTiSb trigonal pyramid. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Dy(1), one Dy(3), one Ti(1), and one Ti(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Dy(1), one Dy(2), one Ti(2), and one Sb(2) atom. In the seventh O site, O(7) is bonded to one Dy(2), one Dy(3), one Ti(2), and one Sb(1) atom to form distorted ODy2TiSb tetrahedra that share corners with two equivalent O(7)Dy2TiSb tetrahedra, corners with two equivalent O(1)NaDy3 tetrahedra, corners with four equivalent O(4)NaDySb2 tetrahedra,  an edgeedge with one O(7)Dy2TiSb tetrahedra, and  an edgeedge with one O(1)NaDy3 tetrahedra.
NaDy3Ti2(SbO7)2 crystallizes in the monoclinic P2/c space group. Na(1) is bonded in a distorted body-centered cubic geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both Na(1)-O(1) bond lengths are 2.36 Å. Both Na(1)-O(2) bond lengths are 2.68 Å. Both Na(1)-O(3) bond lengths are 2.68 Å. Both Na(1)-O(4) bond lengths are 2.57 Å. There are three inequivalent Dy sites. In the first Dy site, Dy(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. Both Dy(1)-O(1) bond lengths are 2.20 Å. Both Dy(1)-O(2) bond lengths are 2.38 Å. Both Dy(1)-O(5) bond lengths are 2.75 Å. Both Dy(1)-O(6) bond lengths are 2.53 Å. In the second Dy site, Dy(2) is bonded to two equivalent O(1), two equivalent O(4), two equivalent O(6), and two equivalent O(7) atoms to form distorted DyO8 hexagonal bipyramids that share edges with two equivalent Dy(3)O8 hexagonal bipyramids, edges with two equivalent Ti(2)O6 octahedra, edges with two equivalent Sb(1)O6 octahedra, and edges with two equivalent Sb(2)O6 octahedra. Both Dy(2)-O(1) bond lengths are 2.20 Å. Both Dy(2)-O(4) bond lengths are 2.47 Å. Both Dy(2)-O(6) bond lengths are 2.55 Å. Both Dy(2)-O(7) bond lengths are 2.56 Å. In the third Dy site, Dy(3) is bonded to two equivalent O(1), two equivalent O(3), two equivalent O(5), and two equivalent O(7) atoms to form distorted DyO8 hexagonal bipyramids that share edges with two equivalent Dy(2)O8 hexagonal bipyramids, edges with two equivalent Ti(1)O6 octahedra, edges with two equivalent Ti(2)O6 octahedra, and edges with two equivalent Sb(1)O6 octahedra. Both Dy(3)-O(1) bond lengths are 2.20 Å. Both Dy(3)-O(3) bond lengths are 2.47 Å. Both Dy(3)-O(5) bond lengths are 2.58 Å. Both Dy(3)-O(7) bond lengths are 2.52 Å. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form TiO6 octahedra that share corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, and edges with two equivalent Dy(3)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-46°. Both Ti(1)-O(2) bond lengths are 2.02 Å. Both Ti(1)-O(3) bond lengths are 1.98 Å. Both Ti(1)-O(5) bond lengths are 1.92 Å. In the second Ti site, Ti(2) is bonded to two equivalent O(5), two equivalent O(6), and two equivalent O(7) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, edges with two equivalent Dy(2)O8 hexagonal bipyramids, and edges with two equivalent Dy(3)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-48°. Both Ti(2)-O(5) bond lengths are 1.94 Å. Both Ti(2)-O(6) bond lengths are 1.99 Å. Both Ti(2)-O(7) bond lengths are 1.98 Å. There are two inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(7) atoms to form SbO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Sb(2)O6 octahedra, edges with two equivalent Dy(2)O8 hexagonal bipyramids, and edges with two equivalent Dy(3)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-49°. Both Sb(1)-O(3) bond lengths are 1.98 Å. Both Sb(1)-O(4) bond lengths are 2.02 Å. Both Sb(1)-O(7) bond lengths are 2.01 Å. In the second Sb site, Sb(2) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form SbO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra, corners with two equivalent Ti(2)O6 octahedra, corners with two equivalent Sb(1)O6 octahedra, and edges with two equivalent Dy(2)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-49°. Both Sb(2)-O(2) bond lengths are 1.98 Å. Both Sb(2)-O(4) bond lengths are 2.02 Å. Both Sb(2)-O(6) bond lengths are 2.00 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Dy(1), one Dy(2), and one Dy(3) atom to form ONaDy3 tetrahedra that share corners with two equivalent O(7)Dy2TiSb tetrahedra, corners with two equivalent O(4)NaDySb2 tetrahedra, corners with four equivalent O(1)NaDy3 tetrahedra, corners with two equivalent O(2)NaDyTiSb trigonal pyramids,  an edgeedge with one O(7)Dy2TiSb tetrahedra,  an edgeedge with one O(4)NaDySb2 tetrahedra, and  an edgeedge with one O(2)NaDyTiSb trigonal pyramid. In the second O site, O(2) is bonded to one Na(1), one Dy(1), one Ti(1), and one Sb(2) atom to form distorted ONaDyTiSb trigonal pyramids that share corners with two equivalent O(1)NaDy3 tetrahedra, corners with two equivalent O(4)NaDySb2 tetrahedra, corners with two equivalent O(2)NaDyTiSb trigonal pyramids,  an edgeedge with one O(1)NaDy3 tetrahedra,  an edgeedge with one O(4)NaDySb2 tetrahedra, and  an edgeedge with one O(2)NaDyTiSb trigonal pyramid. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Na(1), one Dy(3), one Ti(1), and one Sb(1) atom. In the fourth O site, O(4) is bonded to one Na(1), one Dy(2), one Sb(1), and one Sb(2) atom to form distorted ONaDySb2 tetrahedra that share corners with two equivalent O(1)NaDy3 tetrahedra, corners with two equivalent O(4)NaDySb2 tetrahedra, corners with four equivalent O(7)Dy2TiSb tetrahedra, corners with two equivalent O(2)NaDyTiSb trigonal pyramids,  an edgeedge with one O(1)NaDy3 tetrahedra,  an edgeedge with one O(4)NaDySb2 tetrahedra, and  an edgeedge with one O(2)NaDyTiSb trigonal pyramid. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Dy(1), one Dy(3), one Ti(1), and one Ti(2) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Dy(1), one Dy(2), one Ti(2), and one Sb(2) atom. In the seventh O site, O(7) is bonded to one Dy(2), one Dy(3), one Ti(2), and one Sb(1) atom to form distorted ODy2TiSb tetrahedra that share corners with two equivalent O(7)Dy2TiSb tetrahedra, corners with two equivalent O(1)NaDy3 tetrahedra, corners with four equivalent O(4)NaDySb2 tetrahedra,  an edgeedge with one O(7)Dy2TiSb tetrahedra, and  an edgeedge with one O(1)NaDy3 tetrahedra.