Zn2Sb3O8 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form ZnO6 octahedra that share corners with six equivalent Sb(1)O6 octahedra, corners with three equivalent Zn(2)O4 trigonal pyramids, and edges with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. In the second Zn site, Zn(2) is bonded to one O(4) and three equivalent O(2) atoms to form ZnO4 trigonal pyramids that share corners with three equivalent Zn(1)O6 octahedra and corners with nine equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-65°. Sb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Zn(1)O6 octahedra, corners with three equivalent Zn(2)O4 trigonal pyramids,  an edgeedge with one Zn(1)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Zn(1) and two equivalent Sb(1) atoms. In the second O site, O(2) is bonded to one Zn(1), one Zn(2), and two equivalent Sb(1) atoms to form distorted OZn2Sb2 tetrahedra that share corners with two equivalent O(2)Zn2Sb2 tetrahedra,  a cornercorner with one O(4)ZnSb3 trigonal pyramid, edges with two equivalent O(2)Zn2Sb2 tetrahedra, and  an edgeedge with one O(4)ZnSb3 trigonal pyramid. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Sb(1) atoms. In the fourth O site, O(4) is bonded to one Zn(2) and three equivalent Sb(1) atoms to form a mixture of distorted corner and edge-sharing OZnSb3 trigonal pyramids.
Zn2Sb3O8 crystallizes in the hexagonal P6_3mc space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form ZnO6 octahedra that share corners with six equivalent Sb(1)O6 octahedra, corners with three equivalent Zn(2)O4 trigonal pyramids, and edges with three equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. All Zn(1)-O(1) bond lengths are 2.14 Å. All Zn(1)-O(2) bond lengths are 2.31 Å. In the second Zn site, Zn(2) is bonded to one O(4) and three equivalent O(2) atoms to form ZnO4 trigonal pyramids that share corners with three equivalent Zn(1)O6 octahedra and corners with nine equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-65°. The Zn(2)-O(4) bond length is 2.05 Å. All Zn(2)-O(2) bond lengths are 2.09 Å. Sb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form SbO6 octahedra that share corners with two equivalent Zn(1)O6 octahedra, corners with three equivalent Zn(2)O4 trigonal pyramids,  an edgeedge with one Zn(1)O6 octahedra, and edges with four equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles are 52°. The Sb(1)-O(3) bond length is 2.13 Å. The Sb(1)-O(4) bond length is 2.24 Å. Both Sb(1)-O(1) bond lengths are 2.11 Å. Both Sb(1)-O(2) bond lengths are 2.22 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Zn(1) and two equivalent Sb(1) atoms. In the second O site, O(2) is bonded to one Zn(1), one Zn(2), and two equivalent Sb(1) atoms to form distorted OZn2Sb2 tetrahedra that share corners with two equivalent O(2)Zn2Sb2 tetrahedra,  a cornercorner with one O(4)ZnSb3 trigonal pyramid, edges with two equivalent O(2)Zn2Sb2 tetrahedra, and  an edgeedge with one O(4)ZnSb3 trigonal pyramid. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to three equivalent Sb(1) atoms. In the fourth O site, O(4) is bonded to one Zn(2) and three equivalent Sb(1) atoms to form a mixture of distorted corner and edge-sharing OZnSb3 trigonal pyramids.