Bonding of alkali-alkaline earth molecules in the lowest Σ+ states of doublet and quartet multiplicity

\begin{wrapfigure}{r}{0pt} \includegraphics[scale=0.6]{ak_ake.eps} \end{wrapfigure} In the present study the ground state as well as the lowest $^4\Sigma^+$ state were determined for 16 AK-AKE molecules.\footnote{ J. V. Pototschnig, A. W. Hauser and W. E. Ernst, Phys. Chem. Chem. Phys., 2016,18, 5964-5973} Multireference configuration interaction calculations were carried out in order to understand the bonding of diatomic alkali-alkaline earth (AK-AKE) molecules. The correlations between molecular properties (disociation energy, bond distances, electric dipole moment) and atomic properties (electronegativity, polarizability) will be discussed. A correlation between the dissociation energy and the dipole moment of the lowest $^4\Sigma^+$ state was observed, while the dipole moment of the lowest $^2\Sigma^+$ state does not show such a simple dependency. In this case an empirical relation could be established. The class of AK-AKE molecules was selected for this investigation due to their possible applications in ultracold molecular physics