Neptunium diarsenide

Neptunium diarsenide is a binary inorganic compound of neptunium and arsenic with the chemical formula. The compound forms crystals.

Synthesis
Heating stoichiometric amounts of neptunium hydride and arsenic:
 * $$\mathsf{ NpH_x + 2As \ \xrightarrow{450^oC}\ NpAs_2 + (x/2)H_2 }$$

Physical properties
Neptunium diarsenide forms crystals of the tetragonal system, space group P4/nmm, cell parameters a = 0.3958 nm, c = 0.8098 nm.