Holographic Methods in X-Ray Crystallography

In principle, the X-rays that are diffracted by a crystal provide enough information to determine the distribution of electron density in the crystal. However, due to fundamental limitations on how X-rays are detected, some of the information about these diffracted X-rays is lost. Specifically, the amplitudes of the diffracted X-rays are measured but not their phases. Furthermore, due to the sampling limitations imposed by the Bragg condition, the amplitudes of the diffraction data are not sufficient to uniquely define an electron density distribution. Instead there is a range of electron densities compatible with a given set of experimentally measured structure factor amplitudes.