Some Features of the Electron Exchange between Ions and a Metal Surface Caused by its Atomic Structure

Abstract: Some features of the electron exchange between ions and a metal surface caused by its atomic structure are studied. The simulation is based on three-dimensional implementation of the wave-packet propagation method using pseudopotentials describing the metal at the atomic level. Three-dimensional pseudopotentials for the Cu(100), Cu(110), and Cu(111) surfaces, which reproduce well-known electron-exchange regularities well, are constructed using density functional theory. When considering the model “static” problem, it is shown that the lateral position of an ion weakly affects the main characteristics of the electron exchange and ion propagation along one of the directions in the crystal. However, three-dimensional pseudopotentials taking the atomic structure of the metal into account make it possible to obtain a more realistic picture of the electron transition than widely used one-dimensional model pseudopotentials. For example, when simulating grazing scattering with the use of one-dimensional pseudopotentials, the electron retains the parallel velocity component after the passing to the metal, which is contrary to fact. If three-dimensional potentials are used, then the parallel component of the electron velocity in the metal decreases, which is more correct.