  To describe chemical ordering in solid solutions systems Warren-Cowley
short-range parameters are ordinarily used. However, they are not directly
suited for application to long-range ordered systems, as they do not converge
to zero for large separations. It is the aim of this paper to generalize the
theory to long-range ordered systems and quantitatively discuss chemical
short-range order beyond the superstructure arrangements. This is demonstrated
on the example of a non-stoichiometric B2-ordered intermetallic alloy.
Parameters of interatomic potentials are taken from an embedded atom method
(EAM) calculations and the degree of order is simulated by the Monte Carlo
method. Both on-lattice and off-lattice methods, where the latter allows
individual atoms to deviate from their regular lattice sites, were used, and
the resulting effects are discussed.
