  In this publication we introduce SAMPLE, a structure search approach for
commensurate organic monolayers on inorganic substrates. Such monolayers often
show rich polymorphism with diverse molecular arrangements in differently
shaped unit cells. Determining the different commensurate polymorphs from first
principles poses a major challenge due to the large number of possible
molecular arrangements. To meet this challenge, SAMPLE employs coarse-grained
modeling in combination with Bayesian linear regression to efficiently map the
minima of the potential energy surface. In addition, it uses ab initio
thermodynamics to generate phase diagrams. Using the example of naphthalene on
Cu(111), we comprehensively explain the SAMPLE approach and demonstrate its
capabilities by comparing the predicted with the experimentally observed
polymorphs.
