From Online Dictionary of Crystallography
Resonant scattering and synchrotron experiments
The current definition says:
The real and imaginary terms, [math] f\,', f\,''[/math], in the atomic scattering factor are independent of sin(θ)/λ and in general small compared with [math]f_o[/math].
I wonder if the statement small compared with [math]f_o[/math] does apply also in the case of synchrotron experiments. It's really outside my experience but my attention was recently drawn on such statement as being valid only for classical, laboratory experiments. If that is the case, perhaps one should add a note or a remark. --MassimoNespolo (talk) 17:34, 4 April 2021 (UTC)