We performed ab nitro calculations to Investigate the lowest triplet and singlet electronic states of the NO Chiller and their mutual spin-orbit couplings The electronic structure calculations; are done using multiconfigurational approaches and a large diffuse basis set A high density of electronic states is found favoring their mutual interactions by vibronic and spin-orbit couplings. We Used our potential curves and spin-orbit couplings to discuss, thee mechanisms for the IR dissociation and the UV photodissociation of the NO dimer and the electronic de-excitation of NO (A(2)Sigma(+)) after collision with NO (X-2 Pi) For these reactions, multistep pathways, which involve the long-range and the molecular regions of the potential energy surfaces of the triplet and singlet electronic states of N2O2, are suggested. A qualitative agreement between our findings and previous experimental assumptions is found.