Additional Topics

Abstract

So far in this book, the calculation of structure factors F _c for a structure model has assumed classical, elastic scattering of X-rays, in which the scattering atoms alter the radiation neither in amplitude nor in phase (except for the phase shift of π implicit in the scattering of electromagnetic waves). The calculation has been based on atomic scattering factors f _i whose vectorial addition takes into consideration the displacements of the atoms from the origin to evaluate the overall phase and amplitude of each reflection. For centrosymmetric structures, the Friedel Law is strictly adhered to, and the reflections hkl and % MathType!MTEF!2!1!+- % feaagCart1ev2aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn % hiov2DGi1BTfMBaeXatLxBI9gBaerbd9wDYLwzYbItLDharqqtubsr % 4rNCHbWexLMBbXgBd9gzLbvyNv2CaeHbl7mZLdGeaGqiVu0Je9sqqr % pepC0xbbL8F4rqqrFfpeea0xe9Lq-Jc9vqaqpepm0xbba9pwe9Q8fs % 0-yqaqpepae9pg0FirpepeKkFr0xfr-xfr-xb9adbaqaaeGaciGaai % aabeqaamaabaabauaakeaadaqdaaqaaiaadIgaaaWaa0aaaeaacaWG % RbaaamaanaaabaGaamiBaaaaaaa!4220! \[\overline h \overline k \overline l \] have the same intensity.