Application of generalized quantum defect theory to van der Waals complex bound state calculations

Bound states of atom–diatom van der Waals complexes are calculated in the generalized quantum defect theory framework (GMQDT). Due to very strong interchannel couplings, the diabatic GMQDT formalism is extended in order to account for the strongly closed channels (associated with potential curves lying above the total energy E) in the asymptotic analysis of the wave function. An alternative GMQDT treatment combining diabatic and adiabatic representations is also presented. The influence of these strongly closed channels on the level positions and oscillator strengths is analyzed.