Powder X-ray diffraction 100 years after Roentgen

Some major advances in powder diffraction during the last twenty years are presented. A description of the factors contributing to the diffraction-line overlap problem is followed by the presentation of modern methods used to overcome it. They include fitting techniques, the geometrical reconstruction of the reciprocal lattice and the progresses occurred in the instrumental resolution with conventional monochromatic X-ray sources and synchrotron X-rays. The advances in the determination ab initio of crystal structures from powder diffraction data are presented and the precision obtained is discussed.