Patterson Techniques for Powder Data

The application of the Patterson deconvolution techniques to the ab initio crystal structure solution from powder diffraction data is far from being straightforward, since the efficiency of thesuperposition techniques may be weakened by wrong estimates of the reflection intensities, which can produce non-negligible distortions of the Patterson map. Furthermore powder structures: a) can suffer pseudo-translation effects much more frequently than proteins structures; b) may crystallize in centric space groups; c) often crystallize in high-symmetry space groups where Harker domains more complicated than in the case of proteins occur. The aim of this paper is to apply to a large set of powder data structures a Patterson deconvolution procedure derived from that successfully applied to protein structures.