CaZn2O8 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms to form distorted CaO8 hexagonal bipyramids that share corners with four equivalent Ca(1)O8 hexagonal bipyramids and corners with four equivalent Zn(1)O4 tetrahedra. Zn(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form ZnO4 tetrahedra that share corners with two equivalent Ca(1)O8 hexagonal bipyramids and corners with two equivalent Zn(1)O4 tetrahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Zn(1), and one O(4) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Zn(1), and one O(3) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Zn(1) and one O(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one O(1) atom.
CaZn2O8 crystallizes in the monoclinic P2_1/c space group. Ca(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms to form distorted CaO8 hexagonal bipyramids that share corners with four equivalent Ca(1)O8 hexagonal bipyramids and corners with four equivalent Zn(1)O4 tetrahedra. Both Ca(1)-O(1) bond lengths are 2.39 Å. Both Ca(1)-O(2) bond lengths are 2.37 Å. There are two shorter (2.57 Å) and two longer (2.62 Å) Ca(1)-O(4) bond lengths. Zn(1) is bonded to one O(1), one O(2), and two equivalent O(3) atoms to form ZnO4 tetrahedra that share corners with two equivalent Ca(1)O8 hexagonal bipyramids and corners with two equivalent Zn(1)O4 tetrahedra. The Zn(1)-O(1) bond length is 2.06 Å. The Zn(1)-O(2) bond length is 1.94 Å. There is one shorter (1.93 Å) and one longer (2.01 Å) Zn(1)-O(3) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Zn(1), and one O(4) atom. The O(1)-O(4) bond length is 1.36 Å. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1), one Zn(1), and one O(3) atom. The O(2)-O(3) bond length is 1.50 Å. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Zn(1) and one O(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent Ca(1) and one O(1) atom.