Potassium nitride is an unstable chemical compound. Several syntheses were erroneously claimed in the 19th century, and by 1894 it was assumed that it did not exist. However, a synthesis of this compound was claimed in 2004. It is observed to have the anti-TiI3 structure below 233 K (−40 °C; −40 °F), although a Li3P-type structure should be more stable. Above this temperature, it converts to an orthorhombic phase.