Ground and excited state properties of the polar and paramagnetic RbSr molecule: a comparative study

摘要

This paper deals with the electronic structure of RbSr, a molecule possessingboth a permanent magnetic and electric dipole moment in its own frame allowingits manipulation with external fields. Two complementary ab-initio approachesare used for the ground and lowest excited states: first, an approach relyingon optimized effective core potentials with core polarization potentials basedon a full configuration interaction involving three valence electrons, andsecond, an approach using a small-size effective core potential with 19correlated electrons in the framework of coupled-cluster theory. We have foundexcellent agreement between these two approaches for the ground stateproperties including the permanent dipole moment. We have focused on studies ofexcited states correlated to the two lowest asymptotes Rb(5p)+Sr(5s) andRb(5s)+Sr(5s5p) relevant for ongoing experiments on quantum degenerate gases.We present also the Hund c) case potential curves obtained using atomicspin-orbit constants. These potential curves are an excellent starting pointfor experimental studies of molecular structure of RbSr using high-resolutionspectroscopy.