  Morphologies of adsorbed molecular films are of interest in a wide range of
applications. To study the epitaxial growth of these systems in computer
simulations requires access to long time and length scales and one typically
resorts to kinetic Monte Carlo (KMC) simulations. However, KMC simulations
require as input transition rates and their dependence on external parameters
(such as temperature). Experimental data allows only limited and indirect
access to these rates, and models are often oversimplified. Here we follow a
bottom-up approach and aim to systematically construct all relevant rates for
an example system that has shown interesting properties in experiments,
buckminsterfullerene on a calcium fluoride substrate. We develop classical
force fields (both atomistic and coarse-grained) and perform molecular dynamics
simulations of the elementary transitions in order to derive explicit
expressions for the transition rates with a minimal number of free parameters.
