The intriguing but yet still unexplained experimental results of Hibino and Ogino  (1995, 1996), who observed single defect movement on an Me induced Si(111)(√3 x √3) surface, were revived and theoretically analysed. Using nudged elastic band optimization, the minimal energy path for an Si adatom moving on the ideal and vacancy defected surfaces was obtained and the most probable mechanism of the vacancy mediated single defect diffusion was established. This mechanism was shown to be responsible for the experimentally observed Si adatom movement and predicts a far easier movement of the Me adatom on vacancy defected Me induced Si(111)√3 x √3 surfaces.

First Principle Simulations of the Surface Diffusion of Si and Me Adatoms on the Si(111) √3 x √3-Me surface, Al, Ga, In, Pb. Y.V.Luniakov: Surface Science, 2011, 605[19-20], 1866-71