Signatures of an atomic crystal in the band structure of a C60 thin film

Transport phenomena in molecular materials are intrinsically linked to the orbital character and the degree of localization of the valence states. Here we combine angle-resolved photoemission with photoemission tomography to determine the spatial distribution of all molecular states of the valence band structure of a C60 thin film. While the two most frontier valence states exhibit a strong band dispersion, the states at larger binding energies are characterized by distinct emission patterns in energy and momentum space. Our findings demonstrate the formation of an atomic crystal-like band structure in a molecular solid with delocalized π-like valence states and strongly localized σ states at larger binding energies.