  The string method is a general and flexible strategy to compute the most
probable transition path for an activated process (rare event). We apply here
the atomistic string method in the density field to the Cassie-Wenzel
transition, a central problem in the field of superhydrophobicity. We discuss
in detail the mechanism of wetting of a submerged hydrophobic cavity of
nanometer size and its dependence on the geometry of the cavity. Furthermore,
we discuss the algorithmic analogies between the string method and CREaM
[Giacomello et al., Phys. Rev. Lett. 109, 226102 (2012)], a method inspired by
the string that allows for a faster and simpler computation of the mechanism
and of the free-energy profiles of the wetting process. This approach is
general and can be employed in mesoscale and macroscopic calculations.
