Editing Phase problem (section)

=== Anomalous scattering ===

==== ''[[Single-wavelength anomalous dispersion]]'' (SAD). ====

==== ''[[multi-wavelength anomalous dispersion|Multi-wavelength anomalous dispersion (MAD)]]'' ====
A powerful solution is the ''[[multi-wavelength anomalous dispersion]]'' (MAD) method. In this technique, atoms' inner electrons{{clarify|reason=Which atoms? Special new atoms that are introduced?|date=July 2016}} absorb X-rays of particular wavelengths, and reemit the X-rays after a delay, inducing a phase shift in all of the reflections, known as the ''[[anomalous dispersion]] effect''. Analysis of this phase shift (which may be different for individual reflections) results in a solution for the phases. Since X-ray fluorescence techniques (like this one) require excitation at very specific wavelengths, it is necessary to use [[synchrotron radiation]] when using the MAD method.