Computational theory of reflection high energy electron diffraction

The theory of reflection high energy electron diffraction (RHEED) by crystal surfaces is reviewed, with special emphasis on computational techniques. Multiple scattering is accounted for by solving the Schrodinger equation exactly to obtain the amplitudes of the diffracted beams above the surface. The surface and substrate are divided into atomic layers and the RHEED intensities for the entire system are determined from the scattering properties of the individual layers. Alternative methods for implementing this approach are explained and compared. Recent applications to analysis of real RHEED data are used to illustrate the general theory and it is shown that it can provide very good agreement with experiment. The computational efficiency of RHEED calculations is examined carefully and key bottlenecks are identified. This leads to a new computational technique which is much faster than existing ones. Some problems connected with the implementation of this approach are examined in detail.