A theory of He diffraction and resonance scattering from Cu(115) by the complex coordinate method

Our method for computing specular elastic scattering intensities of atomic beams from a periodically corrugated solid surface, is generalized to include nonspecular diffraction intensities, and is applied to the scattering of a helium beam from the Cu(115) surface for resonance as well as off-resonance incident angles. Using a simple corrugated Morse potential with a one-dimensional corrugation function and reasonable values of its parameters, a remarkable agreement with the experimental resonance line shapes over the entire angular range is obtained for both the specular and a nonspecular diffraction channel. The line shapes are found to be extremely sensitive to the corrugation strength parameter, but quite insensitive to the shape of the surface corrugation.