First principle simulations of the surface diffusion of Si and Me adatoms on the Si(111)3×3-Me surface, Me= Al, Ga, In, Pb

► The different mechanisms of the Si adatoms diffusion are simulated. ► The vacancy mediated mechanism is shown to be most favourable one. ► The calculated activation energy barriers agree with the published experimental results. ► The vacancy mediated mechanism predicts the far more fast movement of Me adatoms.