Computation of photoelectron and Auger-electron diffraction II. Multiple scattering cluster calculation PAD2

In this paper, we describe the second (PAD2) of the suite of computer programs for the calculation of angle-resolved photo- or Auger-electron diffraction intensities, using a concentric-shell algorithm (CSA). The function Of the present program is to evaluate the scattering matrix that relates the wavefunction of an electron immediately after its emission from an atomic core to the wavefield that may be detected outside a sample, using an angular-momentum expansion centered on the emitter atom. This program allows that matrix to be evaluated by any of the following schemes (in ascending order of accuracy, and computer requirements): single scattering (SS), outward multiple scattering (OS) and full multiple scattering (MS). (C) 1998 Elsevier Science B.V.