Multi-slice finite difference method for full potential calculation of low energy electron diffraction spectra

We propose a multi-slice finite difference method for full potential calculation of low energy electron diffraction spectra. This method keeps the accuracy of the original finite difference (FD) method but reduces the required storage memory and computation time by more than two orders of magnitude. The gain in speed and reduction in memory requirement allow, for the first time, full potential LEED spectra calculations to be carried out for many realistic systems. In this method, the unit cell of a crystal is divided into thin slices in the depth direction. The reflection and transmission coefficients of each slice are calculated by the FD method. The final reflectivity of the crystal is obtained by combining contributions from all slices using a simple recurrent formula.