11. C₆₀ Molecules on Surfaces: The Role of Jahn–Teller Effects and Surface Interactions

The molecular orbitals of fullerene molecules on surface substrates can be imaged experimentally using scanning tunnelling microscopy (STM). The observed images are influenced by interactions with the substrate. In addition, for fullerene ions, splitting of the orbitals by the Jahn–Teller (JT) effect also affects the observed images. In this work, we consider the effect of both static and dynamic JT interactions on the images that are expected to be obtained from the fullerene anion C₆₀ ⁻, taking into account interactions with the substrate. Our method is to use Hückel molecular orbital (HMO) theory, which is very simple and quick to implement on a desktop computer. Although our approach is not as rigorous as using density functional theory (DFT), the predicted STM images are almost indistinguishable from published DFT images. Furthermore, it readily allows us to explore different situations, such as different adsorption geometries. Our results are also compared with experimental and simulated STM images in the literature.