Determination of Adsorbed C$_{60}$ Nanostructures by Low-Energy Electron Diffraction*

We have recently extended to nanostructures the basic theoretical capabilities of surface structure determination by Low Energy Electron Diffraction (LEED), by adopting a non-periodic cluster approach and substantially accelerating the computation time for complex structures. In this contribution, we describe two further theoretical enhancements and their application to experimental data for buckyballs adsorbed on a Cu(111) surface. One enhancement addresses occasional situations where strong multiple scattering causes poor convergence: this is solved by treating all scattering within subclusters of a few atoms with accurate matrix inversion. Secondly, for the structure determination of complex nanostructures, an efficient search method is essential: for that purpose a modified version of tensor LEED is adapted to nanostructures, called NanoTensorLEED. We exhibit the resulting ability to analyze detailed nanostructures with the case of buckyballs adsorbed on a Cu(111) surface.