Computational Modeling for Scanning Tunneling Microscopy of Physisorbed Molecules via Ab Initio Quantum Chemistry

Scanning tunneling microscopy images of molecular adsorbates on a graphite surface are modeled using the techniques of electron transfer theory. The results are compared with experimentally determined tunneling probabilities and are shown to be qualitatively (and to some extent quantitatively) in accord with the experimental data. The results provide new insight into the various factors that contribute to the features in STM images of molecular adsorbates.