Cd2V2O7 crystallizes in the monoclinic C2/m space group. V(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form VO4 tetrahedra that share corners with six equivalent Cd(1)O6 pentagonal pyramids and  a cornercorner with one V(1)O4 tetrahedra. Cd(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted CdO6 pentagonal pyramids that share corners with six equivalent V(1)O4 tetrahedra and edges with three equivalent Cd(1)O6 pentagonal pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one V(1) and two equivalent Cd(1) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent V(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one V(1) and two equivalent Cd(1) atoms.
Cd2V2O7 crystallizes in the monoclinic C2/m space group. V(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form VO4 tetrahedra that share corners with six equivalent Cd(1)O6 pentagonal pyramids and  a cornercorner with one V(1)O4 tetrahedra. The V(1)-O(2) bond length is 1.76 Å. The V(1)-O(3) bond length is 1.71 Å. Both V(1)-O(1) bond lengths are 1.71 Å. Cd(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted CdO6 pentagonal pyramids that share corners with six equivalent V(1)O4 tetrahedra and edges with three equivalent Cd(1)O6 pentagonal pyramids. Both Cd(1)-O(3) bond lengths are 2.29 Å. There are two shorter (2.25 Å) and two longer (2.39 Å) Cd(1)-O(1) bond lengths. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one V(1) and two equivalent Cd(1) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent V(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one V(1) and two equivalent Cd(1) atoms.