Photodissociation, charge and atom transfer processes in electronically excited states of N3+ Original Research Article

The collinear dissociation paths for several low lying electronically excited singlet and triplet states of N3+ have been mapped by ab initio calculations. It has been found that the first excited 3Π state is separated by a barrier from its dissociation asymptote, explaining the experimental finding that rotationally resolved photodissociation spectra have been detected. No long-range avoided crossings between the two lowest 3Σ− and 3Π states have been found, implying that the charge and atom transfer processes involving N+, N2+ and N2 occur at closer range. No path has been found which would allow a spontaneous charge transfer N(4S)+N2+(X2Σg+)→N+3P) + N2(X1Σg+). The shapes of the calculated potential energy functions explain also that the opposite reaction is not observed until a threshold energy of about 2.8 eV, though it is endothermic only by 1.043 eV. The vertical excitation energies, geometries of the centrosymmetric structures, and the electronic transition moments for singlet, triplet and quintet states are given.