Three-dimensional N-atom model for computer simulation of impact-collision ion scattering spectroscopy

A new method for a computer simulation of impact-collision ion scattering spectroscopy (ICISS), a three-dimensional N-atom (3DNA) model, has been developed as an extension of the three-dimensional three-atom (3D3A) model [W. Hayami, R. Souda, T. Aizawa, Y. Ishizawa, Surf. Sci. 303 (1994) 247]. This 3DNA model can include arbitrary number of atoms, and the scattering cross-section of the system at an arbitrary scattering angle is analytically calculated as a function of impact parameter only, so that the computational time is as short as that of the 3D3A model. As an example, an ICISS spectrum of a four-atom system has been calculated, showing a different critical angle from the 3D3A model when two shadowcones overlap on the target atom.