ABSTRACT:The H-bonded complexes formed from interaction between NH 2 NO (NA) and H 2 O 2 (HP) have been investigated by using B3LYP and MP2 methods with a wide range of basis sets. We found six H-bonded complexes in which three of them have cyclic structure. Calculations carried out at various levels show that the sevenmembered cyclic structure with O⅐⅐⅐HO and O⅐⅐⅐HN hydrogen bonding interactions is the most stable complex. The large binding energy obtained for A1 complex probably results from a more linear arrangement of the O⅐⅐⅐HON and OOH⅐⅐⅐OH-bonds in the seven-membered structure A1. The natural bond orbital (NBO) analysis and the Bader's quantum theory of atoms in molecules have been used to elucidate the interaction characteristics of the NA-HP complexes. The NBO results reveal that the charge transfer energy corresponds to the H-bond interactions for A1 complex is grater than other complexes. The electrostatic nature of H-bond interactions is predicted from QTAIM analysis.