Atom diffraction from soft periodic scattering potentials: Calculation of diffraction intensities by an extended GR method

We present a calculational procedure to solve the scattering equation for arbitrary repulsive scattering potentials in atom diffraction. The method is based on the GR method, which is a procedure that uses an equal number of R vectors within the surface unit cell and G vectors in the reciprocal lattice for the calculation of the scattering amplitudes. This method has the advantages of being computationally fast, easy to implement, and numerically stable within the Rayleigh limit. Comparison with results of coupled-channel calculations establishes the reliability of this new GR soft-wall method. © 1986 The American Physical Society.