ИСТИНА

It is well-known that the highly excited diatomic states manifold undergoes intermolecular perturbations which are mainly determined by spin-orbit interactions between the numerous close-lying electronic states of different multiplicity. Structure and dynamics of these mutually perturbed states cannot be represented adequately in the framework of the conventional adiabatic (Born-Oppenheimer) approximation. The present talk provides a theoretical overview of the state-of-art deperturbation machinery generally used during the past decades to treat the fully mixed diatomic states with the required spectroscopic accuracy. In particular, the survey describes in details both theoretical and experimental progress in the comprehensive deperturbation analysis of the singlet-triplet complexex of alkali diaatomic molecules containing Rb or Cs atoms. The current interest in alkali heterodiatomic molecules arises from their active utilization in the laser synthesis of the stable ultracold molecular ensembles. This is most often done by laser assembly and cooling based on multi-steps optical cycles involving excited molecular states as intermediates. The search for efficient pathways requires that the highly accurate energetic, radiative and magnetic properties of the intermediate electronic states be available beforehand.