Plutonium selenide is a binary inorganic compound of plutonium and selenium with the chemical formula PuSe.^[1][2] The compound forms black crystals and does not dissolve in water.

Reaction of diplutonium triselenide and plutonium trihydride:

${\displaystyle {\ce {2{Pu2Se3}+2{PuH3}->[{\text{1600 °C}}]4{PuSe}+3{H2}}}}$

Fusion of stoichiometric amounts of pure substances:

${\displaystyle {\ce {{Pu}+{Se}->[{\text{220–1000 °C}}]PuSe}}}$

Plutonium selenide forms black crystals of a cubic system, space group Fm3m, cell parameters a = 0.57934 nm, Z = 4, structure of the NaCl type.^[3][4]

With increasing pressure, two phase transitions occur: at 20 GPa into the trigonal system and at 35 GPa into the cubic system, a structure of the CsCl type.

Its magnetic susceptibility follows the Curie-Weiss law.^[5]