Mercury(II) arsenate, a graphtonite-type structure

Hg 3 (AsO 4 ) 2 is isostructural with Hg 3 (PO 4 ) 2 . Both compounds crystallize with a graphtonite-type structure. As a result of the tendency of mercury(II) to form two short linear bonds, there are deviations in the coordination polyhedra between the two structures although the arrangements of the tetrahedral anions are very similar