Tip-dependent corrugation of graphite in scanning tunneling microscopy

We calculate scanning-tunneling-microscope images of graphite, for various one-atom tips. The results deviate from the s-wave tip model, in some cases severely, depending sensitively upon the tip atom. For relevant atoms, the corrugation of the image is less than 0.3 Å. The small size of the corrugation suggests that mechanical distortions, which enhance the apparent corrugation in experiments with graphite, are even more ubiquitous than has been recognized.