The 2- and 4-frequency versions of a model were developed for a long-range ordered alloy in which  a priori  sub-lattices existed. The model was a natural extension, to the ordered state, of a well-known random alloy model. The Manning formalism for the description of tracer correlation effects in a random alloy was extended to the present case. The model was applicable to any lattice which could be imagined to consist of a combination of 2 sub-lattices, with the same number of sites, in which diffusion required a vacancy jump to occur from one sub-lattice to the other. Previous computer simulation results for a simple cubic lattice, together with new ones, were used to assess the analysis. It was found that general trends in the correlation factors were described very well over the complete frequency range, although the detailed fit was usually better for the faster-moving atomic component.

I.V.Belova, G.E.Murch: Philosophical Magazine A, 1996, 73[1], 117-29