Zn3Ta2O8 crystallizes in the monoclinic C2/c space group. Ta(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form TaO6 octahedra that share corners with three equivalent Zn(1)O4 tetrahedra, corners with five equivalent Zn(2)O4 tetrahedra, and edges with two equivalent Ta(1)O6 octahedra. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form ZnO4 tetrahedra that share corners with six equivalent Ta(1)O6 octahedra and corners with two equivalent Zn(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-60°. In the second Zn site, Zn(2) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form ZnO4 tetrahedra that share corners with five equivalent Ta(1)O6 octahedra,  a cornercorner with one Zn(1)O4 tetrahedra, and  an edgeedge with one Zn(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-61°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ta(1), one Zn(1), and one Zn(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ta(1) and two equivalent Zn(2) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ta(1) and one Zn(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to two equivalent Ta(1) and one Zn(1) atom.
Zn3Ta2O8 crystallizes in the monoclinic C2/c space group. Ta(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form TaO6 octahedra that share corners with three equivalent Zn(1)O4 tetrahedra, corners with five equivalent Zn(2)O4 tetrahedra, and edges with two equivalent Ta(1)O6 octahedra. The Ta(1)-O(1) bond length is 1.91 Å. The Ta(1)-O(2) bond length is 1.89 Å. There is one shorter (1.98 Å) and one longer (2.13 Å) Ta(1)-O(3) bond length. There is one shorter (2.01 Å) and one longer (2.08 Å) Ta(1)-O(4) bond length. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form ZnO4 tetrahedra that share corners with six equivalent Ta(1)O6 octahedra and corners with two equivalent Zn(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 50-60°. Both Zn(1)-O(1) bond lengths are 1.97 Å. Both Zn(1)-O(4) bond lengths are 1.95 Å. In the second Zn site, Zn(2) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form ZnO4 tetrahedra that share corners with five equivalent Ta(1)O6 octahedra,  a cornercorner with one Zn(1)O4 tetrahedra, and  an edgeedge with one Zn(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 47-61°. The Zn(2)-O(1) bond length is 1.96 Å. The Zn(2)-O(3) bond length is 1.92 Å. There is one shorter (1.95 Å) and one longer (2.04 Å) Zn(2)-O(2) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ta(1), one Zn(1), and one Zn(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ta(1) and two equivalent Zn(2) atoms. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ta(1) and one Zn(2) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to two equivalent Ta(1) and one Zn(1) atom.