Einsteinium fluoride is a binary inorganic chemical compound of einsteinium and fluorine with the chemical formula .
Einsteinium fluoride can be precipitated from einsteinium(III) chloride solutions upon reaction with fluoride ions. An alternative preparation procedure is to expose einsteinium(III) oxide to chlorine trifluoride (ClF<sub>3</sub>) or F<sub>2</sub> gas at a pressure of 1âÂÂ2 atmospheres and a temperature between 300 and 400 ðC. The EsF<sub>3</sub> crystal structure is hexagonal, as in californium(III) fluoride (CfF<sub>3</sub>) where the Es<sup>3+</sup> ions are 8-fold coordinated by fluorine ions in a bicapped trigonal prism arrangement.
The compound forms crystals and is insoluble in water.
The compound is reduced by metallic lithium: