Monopositively, dipositively, and tripositively charged cations in which the cationic center is connected to two nitrogen atoms bearing lone-pair electrons have been investigated at the B3LYP/6-31G(d) level of density functional theory. The structural features and the stabilities calculated using isodesmic reactions are interpreted on the basis of the "nitrogen lone-pair conjugation": [P(NH2)(2)](+) + [PH4](+) [H2P(NH2)(2)](+) + [PH2](+) (Delta E = 68.1 kcal/mol); [N(NH2)(2)](+) + [NH4](+) --> [H2N(NH2)(2)](+) + [NH2](+) (Delta E = 153.1 kcal/mol). The Kohn-Sham orbital is given showing the nitrogen lone-pair conjugation in-the [P(NH2)(2)](+) cation. [GRAPHICS]