A fundamental limitation of LEED as a surface-structure probe is the complexity of the theory compared with x-ray scattering from solids. By making one full dynamical calculation for a reference structure we express diffraction from modifications of this structure in first-order perturbation theory. This gives a theory analogous to the x-ray case in that it can be separated into a structure factor and a form factor which is a tensor in the dynamical regime. In many cases the linear dependence on the structure factor gives computational savings approaching ${10}^3$ over conventional methods.

• Received 30 June 1986

DOI:https://doi.org/10.1103/PhysRevLett.57.2951