P. S. Weiss* and D. M. Eigler*
Physical Review Letters 71, 3139 (1993).
We present scanning tunneling microscope images of benzene adsorbed on the Pt{111} surface. We find three distinct types of images for isolated benzene molecules, depending upon the benzene adsorption site. This site dependence is in agreement with recent theoretical calculations, and may limit the usefulness of the scanning tunneling microscope in elucidating the structures of adsorbed molecules.