Cold magnetically trapped2Dgscandium atoms. I. Interaction potential

Abstract

We present a first principles description of the interaction of two ground-state scandium atoms. Scandium has a ${{}^{2}D}_{g}$ ground state. Thirty molecular states correlate to the lowest dissociation limit of the dimer. In the short range, potential energy curves are calculated using second-order $n$-electron valence state perturbation theory. The first-order long-range interaction is calculated at the complete active space self-consistent field level. We determine the second-order long-range dispersion interaction from atomic dynamic polarizabilities at imaginary frequencies. These polarizabilities are calculated using time-dependent density functional theory. We merge the short-range approach with the long-range model to obtain a physical description of the 30 potential energy curves correlating to the ${{}^{2}D}_{g}+{{}^{2}D}_{g}$ limit. Diabatic potentials are presented that can be used in quantum scattering calculations, in order to study Zeeman relaxation of ultracold scandium atoms.