The modulus sum function was introduced and its applicability to the interpretation of projections of reconstructed surfaces was shown. Selected real examples were arranged according to the interpretative complexity of the respective 2-dimensional Patterson maps, and corresponded to the most common types of surface reconstruction represented by a shift of the surface atoms from their ideal positions and by different atom types occupying the surface sites. The former type of reconstruction was often found on (001) semiconductor surfaces and its most characteristic feature was the pairing of neighbouring surface atoms forming dimers, e.g., the In0.04Ga0.96As(001)-p(4 x 2) reconstructed surface. This latter type of reconstruction could be induced by both adsorption of deposited atoms onto the surface, e.g. Sb/Ge(113)-c(2 x 2), or by a new structural arrangement of the substrate, caused by the adsorption of external molecules onto the surface, e.g. C60/Au(110)-p(6 x 5) reconstructed surface.

Real Examples of Surface Reconstructions Determined by Direct Methods. X.Torrelles, J.Rius, A.Hirnet, W.Moritz, M.Pedio, R.Felici, P.Rudolf, M.Capozi, F.Boscherini, S.Heun, B.H.Mueller, S.Ferrer: Journal of Physics - Condensed Matter, 2002, 14[16], 4075-86