Electronic origin of scanning tunneling microscopy images and carbon skeleton orientations of normal alkanes adsorbed on graphite

STM images of organic insulating molecules adsorbed on conducting substrates can only be understood if their electronic origin is known. Images of normal alkanes on graphite (n‐C36H74) is shown in the Figure are interpreted here on the basis of their partial electron density plots ρ(r0,ef), demonstrating that the linear alkanes can “tumble” and change their orientation with respect to the graphite surface.