Figure 4.

Compositional variation of the diffuse scattering width, determined using Lorentzian fits to the W–Δ–W scattering profiles calculated from our Monte Carlo configurations (short-range order parameter α = 0.7, red symbols) compared with the experimental data given in Fig. 1 ▸(f) (black symbols). The curves are error-weighted empirical fits of the form f(x) = (ax + b) + c[x(1 − x)], where the linear term represents a virtual-crystal (mean-field) contribution, and the binomial term captures the deviation that results from inhomogeneous mixing. The key result is that both experiment and calculation indicate broadened diffuse scattering features at intermediate compositions.