The Persistence of the HgCl 2 Molecule in Five New Compounds in the System (NH 4 ) w Hg x Cl y (H 2 O) z with w:x:y:z = 1:5:11:0, 2:3:8:1, 4:3:10:2, 2:1:4:1, and 10:3:16:0

Five new compounds in the system (NH 4 )Cl/HgCl 2 /H 2 O have been obtained as colourless single crystals, (NH 4 )Hg 5 Cl 11 , (NH 4 ) 2 Hg 3 Cl 8 (H 2 O), (NH 4 ) 4 Hg 3 Cl 10 (H 2 O) 2 , (NH 4 ) 2 HgCl 4 (H 2 O), and (NH 4 ) 10 Hg 3 Cl 16 . In all of these, as in HgCl 2 itself, (almost) linear HgCl 2 molecules persist with Hg‐Cl distances varying from 229 to 236 pm. In (NH 4 ) 10 Hg 3 Cl 16 there are also tetrahedra [HgCl 4 ] with d(Hg‐Cl) = 247 pm present. If larger Hg‐Cl distances (of up to 340 pm) are considered as belonging to the coordination sphere of Hg II , the structures may be described as consisting of isolated octahedra and tetrahedra as in (NH 4 ) 10 Hg 3 Cl 16 , edge‐connected chains as in (NH 4 ) 2 HgCl 4 (H 2 O), edge‐connected chains and layers of octahedra as in (NH 4 ) 4 Hg 3 Cl 10 (H 2 O) 2 , corrugated layers of edge‐connected octahedra as in (NH 4 ) 2 Hg 3 Cl 8 (H 2 O), and, finally, a three‐dimensional network of connected six‐ and seven‐coordinate Hg‐Cl polyhedra as in (NH 4 )Hg 5 Cl 11 . The water molecules are never attached to Hg II . The (NH 4 ) + cations, and sometimes Cl − anions, play a role for electroneutrality only.