Pt2Hg2O7 crystallizes in the cubic Fd-3m space group. Pt(1) is bonded to six equivalent O(1) atoms to form PtO6 octahedra that share corners with six equivalent Pt(1)O6 octahedra and edges with six equivalent Hg(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 48°. Hg(1) is bonded to two equivalent O(2) and six equivalent O(1) atoms to form distorted HgO8 hexagonal bipyramids that share edges with six equivalent Hg(1)O8 hexagonal bipyramids and edges with six equivalent Pt(1)O6 octahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Pt(1) and two equivalent Hg(1) atoms to form distorted OHg2Pt2 tetrahedra that share corners with two equivalent O(2)Hg4 tetrahedra, corners with twelve equivalent O(1)Hg2Pt2 tetrahedra,  an edgeedge with one O(2)Hg4 tetrahedra, and edges with four equivalent O(1)Hg2Pt2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Hg(1) atoms to form OHg4 tetrahedra that share corners with four equivalent O(2)Hg4 tetrahedra, corners with twelve equivalent O(1)Hg2Pt2 tetrahedra, and edges with six equivalent O(1)Hg2Pt2 tetrahedra.
Pt2Hg2O7 crystallizes in the cubic Fd-3m space group. Pt(1) is bonded to six equivalent O(1) atoms to form PtO6 octahedra that share corners with six equivalent Pt(1)O6 octahedra and edges with six equivalent Hg(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles are 48°. All Pt(1)-O(1) bond lengths are 1.98 Å. Hg(1) is bonded to two equivalent O(2) and six equivalent O(1) atoms to form distorted HgO8 hexagonal bipyramids that share edges with six equivalent Hg(1)O8 hexagonal bipyramids and edges with six equivalent Pt(1)O6 octahedra. Both Hg(1)-O(2) bond lengths are 2.21 Å. All Hg(1)-O(1) bond lengths are 2.52 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Pt(1) and two equivalent Hg(1) atoms to form distorted OHg2Pt2 tetrahedra that share corners with two equivalent O(2)Hg4 tetrahedra, corners with twelve equivalent O(1)Hg2Pt2 tetrahedra,  an edgeedge with one O(2)Hg4 tetrahedra, and edges with four equivalent O(1)Hg2Pt2 tetrahedra. In the second O site, O(2) is bonded to four equivalent Hg(1) atoms to form OHg4 tetrahedra that share corners with four equivalent O(2)Hg4 tetrahedra, corners with twelve equivalent O(1)Hg2Pt2 tetrahedra, and edges with six equivalent O(1)Hg2Pt2 tetrahedra.