We investigate aspects of N-H center dot center dot center dot N hydrogen bonding in the linear trans-diazene clusters (n = 2-10) such as the N center dot center dot center dot H and N-H lengths, n(N) -> sigma*(N-H) interactions, N center dot center dot center dot H strengths, and frequencies of the N-H stretching vibrations utilizing the DFT/B3LYP theory, the natural bond orbital (NBO) method, and the theory of atoms in molecules ( AIM). Our calculations indicate that the structure and energetics are qualitatively different from the conventional H-bonded systems, which usually exhibit distinct cooperative effects, as cluster size increases. First, a shortening rather than lengthening of the N-H bond is found and thus a blue rather than red shift is predicted. Second, for the title clusters, any sizable cooperative changes in the N-H and N center dot center dot center dot H lengths, n(N) -> sigma*(N-H) charge transfers, N center dot center dot center dot H strengths, and frequencies of the N-H stretching vibrations for the linear H-bonded trans-diazene clusters do not exist. Because the n(N) -> sigma*(N-H) interaction hardly exhibits cooperative effects, the capability of the linear trans- diazene cluster to localize electrons at the N center dot center dot center dot H bond critical point is almost independent of cluster size and thereby leads to the noncooperative changes in the N center dot center dot center dot H lengths and strengths and the N-H stretching frequencies. Third, the dispersion energy is sizable and important; more than 30% of short-range dispersion energy not being reproduced by the DFT leads to the underestimation of the interaction energies by DFT/B3LYP. The calculated nonadditive interaction energies show that, unlike the conventional H- boned systems, the trans-diazene clusters indeed exhibit very weak nonadditive interactions.