Y4W13Si2Sb2O28 crystallizes in the monoclinic C2/m space group. Y(1) is bonded in a 5-coordinate geometry to one O(1), one O(5), and three equivalent O(2) atoms. There are five inequivalent W sites. In the first W site, W(1) is bonded to one O(2), one O(7), one O(8), and two equivalent O(1) atoms to form distorted WO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra and  an edgeedge with one W(1)O5 trigonal bipyramid. In the second W site, W(2) is bonded in a 3-coordinate geometry to one O(1), one O(3), and one O(6) atom. In the third W site, W(3) is bonded in a 6-coordinate geometry to two equivalent O(8) and four equivalent O(5) atoms. In the fourth W site, W(4) is bonded in a 10-coordinate geometry to two equivalent Sb(1), two equivalent O(3), two equivalent O(4), and four equivalent O(6) atoms. In the fifth W site, W(5) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(6), and two equivalent O(8) atoms. Si(1) is bonded to one O(3), one O(4), and two equivalent O(7) atoms to form SiO4 tetrahedra that share corners with two equivalent W(1)O5 trigonal bipyramids. Sb(1) is bonded in a 5-coordinate geometry to one W(4) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Y(1), one W(2), and two equivalent W(1) atoms to form OYW3 tetrahedra that share corners with three equivalent O(2)Y3W tetrahedra,  an edgeedge with one O(2)Y3W tetrahedra, and  an edgeedge with one O(1)YW3 tetrahedra. In the second O site, O(2) is bonded to three equivalent Y(1) and one W(1) atom to form OY3W tetrahedra that share corners with two equivalent O(2)Y3W tetrahedra, corners with three equivalent O(1)YW3 tetrahedra,  an edgeedge with one O(1)YW3 tetrahedra, and edges with two equivalent O(2)Y3W tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to one W(4), two equivalent W(2), and one Si(1) atom. In the fourth O site, O(4) is bonded to one W(4), two equivalent W(5), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OSiW3 tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Y(1) and two equivalent W(3) atoms. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one W(2), one W(4), and one W(5) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one W(1) and one Si(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one W(1), one W(3), and one W(5) atom.
Y4W13Si2Sb2O28 crystallizes in the monoclinic C2/m space group. Y(1) is bonded in a 5-coordinate geometry to one O(1), one O(5), and three equivalent O(2) atoms. The Y(1)-O(1) bond length is 2.24 Å. The Y(1)-O(5) bond length is 2.24 Å. There are a spread of Y(1)-O(2) bond distances ranging from 2.20-2.35 Å. There are five inequivalent W sites. In the first W site, W(1) is bonded to one O(2), one O(7), one O(8), and two equivalent O(1) atoms to form distorted WO5 trigonal bipyramids that share  a cornercorner with one Si(1)O4 tetrahedra and  an edgeedge with one W(1)O5 trigonal bipyramid. The W(1)-O(2) bond length is 2.17 Å. The W(1)-O(7) bond length is 2.07 Å. The W(1)-O(8) bond length is 2.16 Å. There is one shorter (2.19 Å) and one longer (2.24 Å) W(1)-O(1) bond length. In the second W site, W(2) is bonded in a 3-coordinate geometry to one O(1), one O(3), and one O(6) atom. The W(2)-O(1) bond length is 2.09 Å. The W(2)-O(3) bond length is 2.21 Å. The W(2)-O(6) bond length is 1.99 Å. In the third W site, W(3) is bonded in a 6-coordinate geometry to two equivalent O(8) and four equivalent O(5) atoms. Both W(3)-O(8) bond lengths are 2.17 Å. There are two shorter (2.09 Å) and two longer (2.22 Å) W(3)-O(5) bond lengths. In the fourth W site, W(4) is bonded in a 10-coordinate geometry to two equivalent Sb(1), two equivalent O(3), two equivalent O(4), and four equivalent O(6) atoms. Both W(4)-Sb(1) bond lengths are 3.00 Å. Both W(4)-O(3) bond lengths are 2.87 Å. Both W(4)-O(4) bond lengths are 2.25 Å. All W(4)-O(6) bond lengths are 2.57 Å. In the fifth W site, W(5) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(6), and two equivalent O(8) atoms. Both W(5)-O(4) bond lengths are 2.44 Å. Both W(5)-O(6) bond lengths are 2.03 Å. Both W(5)-O(8) bond lengths are 2.09 Å. Si(1) is bonded to one O(3), one O(4), and two equivalent O(7) atoms to form SiO4 tetrahedra that share corners with two equivalent W(1)O5 trigonal bipyramids. The Si(1)-O(3) bond length is 1.69 Å. The Si(1)-O(4) bond length is 1.71 Å. Both Si(1)-O(7) bond lengths are 1.59 Å. Sb(1) is bonded in a 5-coordinate geometry to one W(4) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Y(1), one W(2), and two equivalent W(1) atoms to form OYW3 tetrahedra that share corners with three equivalent O(2)Y3W tetrahedra,  an edgeedge with one O(2)Y3W tetrahedra, and  an edgeedge with one O(1)YW3 tetrahedra. In the second O site, O(2) is bonded to three equivalent Y(1) and one W(1) atom to form OY3W tetrahedra that share corners with two equivalent O(2)Y3W tetrahedra, corners with three equivalent O(1)YW3 tetrahedra,  an edgeedge with one O(1)YW3 tetrahedra, and edges with two equivalent O(2)Y3W tetrahedra. In the third O site, O(3) is bonded in a 3-coordinate geometry to one W(4), two equivalent W(2), and one Si(1) atom. In the fourth O site, O(4) is bonded to one W(4), two equivalent W(5), and one Si(1) atom to form a mixture of distorted edge and corner-sharing OSiW3 tetrahedra. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Y(1) and two equivalent W(3) atoms. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one W(2), one W(4), and one W(5) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one W(1) and one Si(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one W(1), one W(3), and one W(5) atom.