Caesium triiodide

Caesium triiodide is an inorganic compound, with the chemical formula of CsI3. It can be prepared by slow volatilization and crystallization of caesium iodide and iodine in aqueous ethanol solution. It can form precipitates with diazobenzene.

It undergoes a phase transition from Pnma to P-3c1 under high pressure, and its structure changes from layered to 3D.