  We investigate the energetics of the atom exchange reaction in the
SrF+alkali-metal atom and CaF+alkali-metal atom systems. Such reactions are
possible only for collisions of SrF and CaF with the lithium atoms, while they
are energetically forbidden for other alkali-metal atoms. Specifically, we
focus on SrF interacting with Li, Rb, and Sr atoms and use ab initio methods to
demonstrate that the SrF+Li and SrF+Sr reactions are barrierless. We present
potential energy surfaces for the interaction of the SrF molecule with the Li,
Rb, and Sr atoms in their energetically lowest-lying electronic spin states.
The obtained potential energy surfaces are deep and exhibit profound
interaction anisotropies. We predict that the collisions of SrF molecules in
the rotational or Zeeman excited states most likely have a strong inelastic
character. We discuss the prospects for the sympathetic cooling of SrF and CaF
molecules using ultracold alkali-metal atoms.
