A numerically manageable formalism for the dynamical calculation of di
ffuse reflection high-energy electron diffraction (RHEED) is presented
. The diffuse scattering arises from transitions between dynamically c
alculated scattering states in the periodic part of the scattering pot
ential and the nonperiodic part is treated as a perturbation. For atom
s placed on equivalent lattice sites relative to the periodic-potentia
l part, the formalism allows us to treat disorder scattering by kinema
tical structure factors that have to be multiplied by dynamically calc
ulated atomic-scattering amplitudes so that the statistics of the diso
rder can be treated independently of the dynamical calculations. It is
shown that azimuthal reflection profiles (parallel to the shadow edge
) can, in favorable cases, be interpreted kinematically whereas polar
profiles (normal to the shadow edge) are strongly influenced dynamical
ly. It is further demonstrated by model calculations for the diffuse R
HEED from disordered adsorbate layers that the corresponding broad sca
ttering distribution depends strongly on the position of the adsorbate
relative to the substrate. This should enable the use of RHEED in the
field of structure analysis of disordered adsorbate layers. Finally,
our concept is applied to thermal diffuse scattering. We show that the
main structures of a measured broad thermal-diffuse-scattering distri
bution from Pt(110) can be explained with the Einstein model, i.e., in
dependent atomic oscillations.