{\it Ab initio} potential energy surfaces $1 ^4A'$, $2 ^4A'$, $1 ^4A''$ and $2 ^4A''$ of Li$_3$ in a constant external magnetic field

Molecular potentail energy surfaces (PESs) have played an essential role in understanding the field-induced interactions in atomic/molecular systems. External magnetic fields are relevant because they are used to control the pairwise interactions in atomic quantum gases. We present accurate PESs for three fermionic $^6$Li atoms under a constant external magnetic field. Calculations are made using the diatomics-in-molecules method [1], accounting for fine and hyperfine interactions. PESs are constructed using full configuration interaction for the three valence electrons, and a global-fit method [2] is used to obtain the three-body terms. These PESs can be used, for example, to study three-body recombination near overlapping Feshbach resonances. \\[4pt] [1] J. C. Tully, J. Chem. Phys. {\bf 58}, 1396 (1973) \newline [2] A. Aguado {\it et al.}, Comput. Phys. Commun. {\bf 108}, 259 (1998)