Coexisting inequivalent orientations of C-60 on Ag(001) - art. no. 125406

X-ray photoelectron diffraction has been used to determine the molecular or ientation of C-60 adsorbed as a monolayer on the Ag(001) surface. From an e xtended comparison to single scattering cluster calculations, we find the p resence of two inequivalent prevailing molecular orientations of the C-60 c age, as well as a considerable fraction of rotationally not-ordered molecul es. In this system, scanning tunneling microscopy (STM) investigations have shown the presence of two differently imaged molecules that the authors pr oposed to originate from different bonding states [E. Giudice et al, Surf. Sci. 405, L561 (1998)]. Our analysis suggests a relation between imaging pr operty and rotational order or not-order, while the two prevailing orientat ions are not distinguished by the existing STM data in this case.