STM images showing the diffusion of a single dimer along a dimer row at 410K. Unlike our other movies, this is composed of empty state images, so the surface rows appear dark and the troughs appear bright. The dimer's orientation flips between parallel and perpendicular to the rows (types A and B respectively) while it progresses along the row; however, at this temperature the two orientations are indistinguishable. Schematics of these orientations can be viewed in the gallery. Also available there, is an animation illustrating both along the row and across the rows diffusion modes. The newly discovered across the rows mode is documented in the Stealth Mode Diffusion movie. Size= 166 × 166 Å Frame Rate= 1/18sec. Click on image to return to still frame.