  By means of ab initio and tight-binding calculations it is shown that
metastable nitrogen clusters N_8 (boats) can form quasi-one-dimensional
ensembles in which the nearest clusters N_8 are bound to each other by covalent
bonds. Those ensembles are characterized by rather high energy barriers (~ 0.3
eV) that prevent the fission of the ensembles into isolated N_8 clusters and/or
N_2 molecules.
