  Macromolecules can form regular structures on inert surfaces. We have
developed a combined empirical and modeling approach to derive the bonding.
From experimental scanning tunneling microscopy (STM) images of structures
formed on Au(111) by melamine, by PTCDA, and by a 2:3 mixture of the two, we
determine the molecular bonding morphologies. Within these bonding morphologies
and recognizing the distinction between cohesive and adhesive molecular
interactions we simultaneously simulated different molecular structures using a
lattice Monte Carlo method. Within these bonding morphologies there is a
distinction between cohesive and adhesive molecular interactions. We have
simulated different molecular structures using a lattice Monte Carlo method.
