Intermediate coupling strength pre-dissociation of diatomic molecules: transition from diabatic to adiabatic case Original Research Article

Many diatomic molecular systems have overlapping potential curves and it is well known that if the electronic states are of the same symmetry then the adiabatic curves undergo an avoided crossing. Photo-absorption to these states have interesting spectroscopic properties including Fano profile line shapes and the possibility of very narrow line widths above the dissociation limit. A novel interpretation of the change in resonance structure between the diabatic and adiabatic limit based on combined bound vibrational functions is presented and compared with results obtained by the Siegert-complex energy method for a model MgH system.