An [Hg
6O
2]-cationic (
r) octahedron atomic group has been isolated in a number of mercury oxohalide structures. The octahedron is constructed from two edge-sharing oxo-centered [Hg
4O] tetrahedra. For
-Hg
3O
2Cl
2,
-Hg
3O
2Cl
2, Hg
2OI, [Hg
2]
3O
2Cl
2, [Hg
2]
3HgO
3Cl
2, Hg
5O
4Cl
2, and some other compounds, the geometrical parameters of their crystal structures depend on the dimensions and mutual packing of the cationic
r-octahedra and the individual [Hg
4O] tetrahedra, if any.
structures of mercury oxohalides - crystal structure fragmentation - [Hg6O2]—r-octahedron group