Real examples of surface reconstructions determined by direct methods

In this work the modulus sum function is briefly introduced and its applicability to the automated interpretation of projections of reconstructed surfaces shown. The selected real examples have been arranged according to the interpretation complexity of the respective two-dimensional Patterson maps and correspond to the most common types of surface reconstructions represented by: (i) a shift of the surface atoms from their ideal positions. This type of reconstruction is often found on (001) semiconductor surfaces and its most characteristic structural feature is the pairing of neighbouring surface atoms forming dimers, e.g., the In0.04Ga0.96As(001)-p(4 x 2) reconstructed surface. (ii) Different atom types occupying the surface sites. This type of reconstruction can be induced by both the adsorption of deposited atoms onto the surface, e.g. Sb/Ge(113)-c(2 x 2), or a new structural arrangement of the substrate caused by the adsorption of external molecules onto the surface, e.g C-60/Au(110)-p(6 x 5) reconstructed surface.