Potassium nitride

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- structure below , although a -type structure should be more stable. Above this temperature, it converts to an orthorhombic phase.