Solving crystal structures using reciprocal space methods

The RS methods, the best choice for the solution of small and medium size crystal structure from single crystal diffraction data, have been modified in order to succeed in solution from powder data also. In particular, the phasing process and the procedures of structure model optimization have been strengthened for facing the problems due to peak overlap. The RS methods have the great advantage of requiring few starting information: the experimental pattern, the cell parameters, the space group and the chemical formula. Their dependence on the quality of experimental pattern, in particular on the peak resolution, is a serious limit which can be overcome in many cases. Of course, the use of synchrotron radiation is always advantageous and to be preferred. Anyway, the progress up to now reached, makes us to state that, in general, medium quality conventional laboratory diffractometer X-ray data with RES better than 1.4 Å can be successfully used for solving inorganic as well organic compounds by RS methods.