  We present a study of the potential energy surface (PES) of anthracene,
tetracene and pentacene clusters with up to 30 molecules. We have applied the
basin-hopping Monte Carlo (BHMC) algorithm to clusters of acene molecules in
order to find their lowest energy states. The acene molecules are described by
the polymer-consistent force field - interface force field (PCFF-IFF). We
present the structures with the lowest observed energy, and we discuss the
relative stability and accessibility of structures corresponding to local
energy minima.
