Adiabatic picture and decay mechanism

Provided the coupling between the dissociation and the internal coordinates is not too strong, the adiabatic approximation, outlined in Section 

provides a simple picture of resonances in full as well as half collisions. The adiabatic potential curves en(R) defined by solving the onedimensional Schrodinger equation (3.31) are crutial. For a quantitative analysis, however, one should correct the vibrational energies by taking into account the diagonal elements of the nonadiabatic matrix U defined in (3.35) which can be considered as additional energy terms [see the left-hand side of Equation (3.33) Romelt 1983 Child 1991 ch.l0].t 

The quasi-bound states can dissociate by tunneling through the potential barrier and/or by vibrational quenching. In the latter case energy 

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