Abstract: Possible geometrical structures and relative stability of alkali metal nitride compound (K₃N)_n(n=1,…,5) clusters are studied with a hybrid density functional theory(B3LYP)with 6-311*-basis sets.Bond property,charge distribution,vibrational property and stabilities of the stablest isomers of (K₃N)_n(n=1,…,5)clusters are analyzed.It shows that the stablest isomers of (K₃N)_n(n=1,…,5) clusters are changing gradually from planar structure to three-dimensional structure.(K₃N)₄ and (K₃N)₅ are layered structure similar to crystal.Coordination rlnmhers of N atoms are usually 5 or 6.Natural charges of N atom and K atom are about-1.608e and+0.550e.respectively.A strong ionic bond exists between K atom and N atom.Dynamic stability of (K₃N)₄ cluster is higher than that of other clusters.

Key words: (K₃N)_n(n=1,…,5)clusters, density functional theory, structure and properties