ABSTRACT:The reaction of N ( 2 D) radical with NO 2 molecule has been studied theoretically using density functional theory and ab initio quantum chemistry method. Singlet electronic state [N 2 O 2 ] potential energy surfaces (PES) are calculated at the CCSD(T)/aug-cc-pVDZ//B3LYP/6-311ϩG(d) ϩ ZPE and G3B3 levels of theory. All the involved transition states for generation of (2NO) and (O 2 ϩ N 2 ) lie much lower than the reactants. Thus, the novel reaction N ϩ NO 2 can proceed effectively even at low temperatures and it is expected to play a role in both combustion and interstellar processes. On the basis of the analysis of the kinetics of all pathways through which the reactions proceed, we expect that the competitive power of reaction pathways may vary with experimental conditions for the title reaction.