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Within the scope of the self-consistent-field (SCF) and mean-SCF approximations, the Matsubara–Kanzaki–Krivoglaz lattice-statics method as well as the Krivoglaz–Clapp–Moss approach, the kinematic diffuse scattering intensities near the Bragg reflection caused by the atomic short-range order (taking into account the long-range magnetic order) in a (para)magnetic bulk face-centred cubic Ni–Fe alloy are investigated in detail. The reciprocal-space symmetry analysis of both the `direct' `electrochemical' and short-range `exchange' interactions as well as the long-range `indirect' `strain-induced' contribution to the Fourier components of interatomic `mixing' energies and the diffuse scattering intensity contributions near the `fundamental' Γ(000)-point is carried out. In the Γ-point vicinity, the rigorous symmetry regularities for all the energy and diffuse scattering intensity contributions are formulated. As revealed, the short-range order (SRO) diffuse scattering intensity behaves conditionally as I_{{\rm SRO}}({\bf k}) \propto k^{2} for {\bf k} \rightarrow {\bf 0} from all the reciprocal-space directions, which is in contrast to the conventional Huang diffuse scattering intensity conditionally definable as I_{{\rm Huang}}({\bf k}) \propto k^{-2} for {\bf k} \rightarrow {\bf 0}. Special attention is paid to the analytic (i.e. azimuthal) and nonanalytic (i.e. first-kind-jump-discontinuous `radial') behaviours of the Fourier components of interatomic `mixing' energies or the SRO intensities near and at the Γ(000)-point.

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Portable Document Format (PDF) file https://doi.org/10.1107/S0108767313018138/ib5019sup1.pdf
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