Using low-temperature scanning tunneling microscopy we find that perylenetetracarboxylic-dianhydride on Au(788) exhibits three coexisting adsorption phases. Single-molecule tunneling spectroscopy reveals orbital energies, which differ in the different adsorption phases. Density functional theory calculations associate the experimentally observed submolecular corrugation to the spatial distribution of the second-to-lowest unoccupied molecular orbital. We tentatively attribute the orbital shifts to a varying number of hydrogen bonds.
@article{arxiv.cond-mat/0506025,
title = {Molecular Orbital Shift of Perylenetetracarboxylic-Dianhydride},
author = {J. Kroeger and H. Jensen and R. Berndt and R. Rurali and N. Lorente},
journal= {arXiv preprint arXiv:cond-mat/0506025},
year = {2007}
}