Y4Sn13Si2(SbO14)2 crystallizes in the monoclinic C2/m space group. Y(1) is bonded to one O(1), one O(5), and three equivalent O(2) atoms to form distorted YO5 trigonal bipyramids that share  a cornercorner with one Sb(1)O6 octahedra, corners with two equivalent Y(1)O5 trigonal bipyramids, and edges with two equivalent Y(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 46°. There are five inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 4-coordinate geometry to one O(7), one O(8), and two equivalent O(1) atoms. In the second Sn site, Sn(2) is bonded in a distorted T-shaped geometry to one O(1), one O(3), and one O(6) atom. In the third Sn site, Sn(3) is bonded in a 4-coordinate geometry to two equivalent O(5) and two equivalent O(8) atoms. In the fourth Sn site, Sn(4) is bonded to two equivalent O(3), two equivalent O(4), and four equivalent O(6) atoms to form distorted SnO8 hexagonal bipyramids that share edges with two equivalent Sb(1)O6 octahedra and edges with two equivalent Si(1)O4 tetrahedra. In the fifth Sn site, Sn(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  an edgeedge with one Sn(4)O8 hexagonal bipyramid. Sb(1) is bonded to two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms to form SbO6 octahedra that share corners with two equivalent Y(1)O5 trigonal bipyramids and  an edgeedge with one Sn(4)O8 hexagonal bipyramid. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Y(1), one Sn(2), and two equivalent Sn(1) atoms to form distorted OYSn3 tetrahedra that share  a cornercorner with one O(3)SiSn3 tetrahedra, corners with two equivalent O(8)Sn3Sb trigonal pyramids, and  an edgeedge with one O(1)YSn3 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to three equivalent Y(1) atoms. In the third O site, O(3) is bonded to one Sn(4), two equivalent Sn(2), and one Si(1) atom to form distorted OSiSn3 tetrahedra that share  a cornercorner with one O(3)SiSn3 tetrahedra and corners with two equivalent O(1)YSn3 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sn(4), two equivalent Sn(5), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Y(1), one Sn(3), and one Sb(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sn(2), one Sn(4), one Sn(5), and one Sb(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Sn(1) and one Si(1) atom. In the eighth O site, O(8) is bonded to one Sn(1), one Sn(3), one Sn(5), and one Sb(1) atom to form distorted OSn3Sb trigonal pyramids that share corners with two equivalent O(1)YSn3 tetrahedra,  a cornercorner with one O(8)Sn3Sb trigonal pyramid, and  an edgeedge with one O(8)Sn3Sb trigonal pyramid.
Y4Sn13Si2(SbO14)2 crystallizes in the monoclinic C2/m space group. Y(1) is bonded to one O(1), one O(5), and three equivalent O(2) atoms to form distorted YO5 trigonal bipyramids that share  a cornercorner with one Sb(1)O6 octahedra, corners with two equivalent Y(1)O5 trigonal bipyramids, and edges with two equivalent Y(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 46°. The Y(1)-O(1) bond length is 2.28 Å. The Y(1)-O(5) bond length is 2.26 Å. There are a spread of Y(1)-O(2) bond distances ranging from 2.15-2.45 Å. There are five inequivalent Sn sites. In the first Sn site, Sn(1) is bonded in a 4-coordinate geometry to one O(7), one O(8), and two equivalent O(1) atoms. The Sn(1)-O(7) bond length is 2.17 Å. The Sn(1)-O(8) bond length is 2.30 Å. There is one shorter (2.13 Å) and one longer (2.62 Å) Sn(1)-O(1) bond length. In the second Sn site, Sn(2) is bonded in a distorted T-shaped geometry to one O(1), one O(3), and one O(6) atom. The Sn(2)-O(1) bond length is 2.22 Å. The Sn(2)-O(3) bond length is 2.32 Å. The Sn(2)-O(6) bond length is 2.15 Å. In the third Sn site, Sn(3) is bonded in a 4-coordinate geometry to two equivalent O(5) and two equivalent O(8) atoms. Both Sn(3)-O(5) bond lengths are 2.53 Å. Both Sn(3)-O(8) bond lengths are 2.31 Å. In the fourth Sn site, Sn(4) is bonded to two equivalent O(3), two equivalent O(4), and four equivalent O(6) atoms to form distorted SnO8 hexagonal bipyramids that share edges with two equivalent Sb(1)O6 octahedra and edges with two equivalent Si(1)O4 tetrahedra. Both Sn(4)-O(3) bond lengths are 2.52 Å. Both Sn(4)-O(4) bond lengths are 2.66 Å. All Sn(4)-O(6) bond lengths are 2.72 Å. In the fifth Sn site, Sn(5) is bonded in a 6-coordinate geometry to two equivalent O(4), two equivalent O(6), and two equivalent O(8) atoms. Both Sn(5)-O(4) bond lengths are 2.37 Å. Both Sn(5)-O(6) bond lengths are 2.62 Å. Both Sn(5)-O(8) bond lengths are 2.68 Å. Si(1) is bonded to one O(3), one O(4), and two equivalent O(7) atoms to form SiO4 tetrahedra that share  an edgeedge with one Sn(4)O8 hexagonal bipyramid. The Si(1)-O(3) bond length is 1.68 Å. The Si(1)-O(4) bond length is 1.67 Å. Both Si(1)-O(7) bond lengths are 1.62 Å. Sb(1) is bonded to two equivalent O(5), two equivalent O(6), and two equivalent O(8) atoms to form SbO6 octahedra that share corners with two equivalent Y(1)O5 trigonal bipyramids and  an edgeedge with one Sn(4)O8 hexagonal bipyramid. Both Sb(1)-O(5) bond lengths are 2.01 Å. Both Sb(1)-O(6) bond lengths are 2.07 Å. Both Sb(1)-O(8) bond lengths are 2.08 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Y(1), one Sn(2), and two equivalent Sn(1) atoms to form distorted OYSn3 tetrahedra that share  a cornercorner with one O(3)SiSn3 tetrahedra, corners with two equivalent O(8)Sn3Sb trigonal pyramids, and  an edgeedge with one O(1)YSn3 tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to three equivalent Y(1) atoms. In the third O site, O(3) is bonded to one Sn(4), two equivalent Sn(2), and one Si(1) atom to form distorted OSiSn3 tetrahedra that share  a cornercorner with one O(3)SiSn3 tetrahedra and corners with two equivalent O(1)YSn3 tetrahedra. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sn(4), two equivalent Sn(5), and one Si(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Y(1), one Sn(3), and one Sb(1) atom. In the sixth O site, O(6) is bonded in a 4-coordinate geometry to one Sn(2), one Sn(4), one Sn(5), and one Sb(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Sn(1) and one Si(1) atom. In the eighth O site, O(8) is bonded to one Sn(1), one Sn(3), one Sn(5), and one Sb(1) atom to form distorted OSn3Sb trigonal pyramids that share corners with two equivalent O(1)YSn3 tetrahedra,  a cornercorner with one O(8)Sn3Sb trigonal pyramid, and  an edgeedge with one O(8)Sn3Sb trigonal pyramid.