Simulating adsorption of complex molecules using the linearity between interaction energies and tunnelling currents: The case of hexabenzocoronene on a Ag/Pt dislocation network

Abstract

We present a method for determining the adsorption position of complex molecules on surfaces from first-principles calculations. We use electron transport theory through a vacuum barrier (theory of scanning tunnelling microscopy), and the relationship between the tunnelling current and the interaction energy between surface and tip. This method is especially useful for obtaining reasonable adsorption positions of relatively large molecules (> 50 atoms) on reconstructed surfaces, e.g. dislocation networks. The main advantage is that this approach is computationally efficient and does not require mapping of all adsorption sites by separate simulations. The reliability is illustrated by simulating the adsorption of hexabenzocoronene on a model Ag/Pt(111) surface. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.