Figure 2. A two-dimensional solid-solution structure.

Schematic diagram showing the distribution of solute atoms (yellow circles) in a square lattice of solvent atoms (light red circles). The major part of this structure can be represented by a local structural unit, formulated as [solute₁-solvent₄]solute₁, which covers only the 1^st-neighbors [solute₁-solvent₄] cluster (marked with a large blue circle) and one 2^nd-neighbor solute as the glue atom (linked to the cluster center by a blue line segment).