  Droplet nucleation and evaporation are ubiquitous in nature and many
technological applications, such as phase-change cooling and boiling heat
transfer. So far, the description of these phenomena at the molecular scale has
posed challenges for modelling with most of the models being implemented on a
lattice. Here, we propose an {off-lattice} Monte-Carlo approach combined with a
grid that can be used for the investigation of droplet formation and
evaporation. We provide the details of the model, its implementation as Python
code, and results illustrating its dependence on various parameters. The method
can be easily extended for any force-field ({e.g.,} coarse-grained, all-atom
models, and external fields, such as gravity and electric field). Thus, we
anticipate that the proposed model will offer opportunities for a wide range of
studies in various research areas involving droplet formation and evaporation
and will also form the basis for further method developments for the molecular
modelling of such phenomena.
