Determination of crystal structures with large known fragments directly from measured X-ray powder diffraction intensities

A strategy for the determination of crystal structures with large known fragments directly from measured X-ray powder diffraction intensities is presented. It is based on the automated full-symmetry Patterson search method described by Rius & Miravitlles [J. Appl. Cryst. (1987). 20, 261-269] where the Fourier coefficients of the observed Patterson function are modified to allow the use of powder diffraction intensity data. Its application to two structures, one with simulated and one with experimental data, is shown.