Raman spectra show that the molecules distort at higher pressures.

Between 16-20 kbar, the structure undergoes a phase transition as the Hg(II) center changes from 2- to 4-coordinate as the CN groups bind to neighboring Hg centers forming via Hg-N bonds.

[6] As in the solid state, in aqueous solution, Hg(CN)2 molecules are linear.

[2] Mercuric cyanide is formed from aqueous hydrogen cyanide and mercuric oxide:[7] Hg(CN)2 can also be prepared by mixing HgO with finely powdered Prussian blue.

In these reactions, metallic mercury precipitates, and Hg(CN)2 remains in solution:[8] It rapidly decomposes in acid to give off hydrogen cyanide.