Abstract

The rapid development of experimental techniques to produce cold and ultra-cold molecules opens the ways to manipulate them or to control their formation dy-namics using external fields, and to explore their interactions with surrounding par-ticles. In most cases, the detailed knowledge of the internal molecular structure is re-quired to guide such studies and to interpret their results. For several years now our group carries out systematic theoretical investigations on alkali molecular systems, using a quantum chemistry approach based on pseudopotentials for atomic core rep-resentation, Gaussian basis sets, and effective potentials for core polarization. Poten-tial curves, permanent and transition dipole moments, and static dipole polarizabili-ties have been obtained for all alkali pairs, both homonuclear and heteronuclear, which are relevant for ultracold molecule formation processes. Recent extensions of these studies concern the computation of dynamical po-larizabilities of bialkali molecules, which determine the ability for trapping them in optical lattices during the manipulation of their internal degrees of freedom. Once these molecules are brought into the lowest level of their ground state, we further analyze the competition between their hyperfine structure and the quadratic Stark shifts induced by the optical lattice. Molecules composed of an alkali atom and an alkaline-earth ion (or an Yb+ ion) may also be modelled as effective two-electron systems that we recently addressed with our approach. Preliminary results will be presented for such compounds, in the perspective of the possibility to observe charge exchange process when a cold atom trap is set up together with a cold ion trap. This work is achieved in collaboration with Corentin Pavageau, Romain Vex-iau, Mireille Aymar, and Nadia Bouloufa.