Triple correlations in a AyB1 − y solid solution with a planar hexagonal lattice

It is shown that triple correlations in a A _y B_{1 − y} solid solution with a planar hexagonal lattice are due to the presence of nearest-pair correlations. The admissible range of the triple correlation as a function of the composition of the A _y B_{1 − y} solid solution and pair correlation value is determined. It is shown that periodically ordered planar hexagonal and square-island nanostructures can be considered as A_1/4□ _3/4 solid solutions with vacant sites □ and sites occupied by nanoparticles A. In this case, the ordered distribution of the nanoparticles over the sites of the planar lattice is caused by the nearest-air correlation that is negative in sign and maximal in absolute value.