Effect of n-beam Interaction

Abstract

Weak spurious intensities arising from the n-beam interaction (the multiple diffraction) often obscure the existence of screw axes or glide planes. It is pointed out that the n-beam interaction may also introduce· significantly different intensities to a set of crystallographically equivalent reciprocal lattice points. These problems can be solved by making IJI scanning measurements and, more definitely, by a comparison with the simulation based on the Soejima-Okazaki-Matsumoto (1985) formalism; some examples are shown. Since the influence on the intensity reaches 10% for strong reftections and more for weaker ones, a careful examination is essential for the accurate determination of F values.