SEMINAR ON “STRUCTURE”

The convenor of the seminar, K. Yvon, gave a short summary on major limitations of diffraction methods for crystal structure analysis, and in particular on error estimates of structural parameters (e.s.d.'s) as obtained from neutron and synchrotron X-ray data. In order to be useful for a discussion of physical and chemical properties, interatomic distances (bond lengths) should be known to an accuracy of better than 0.1%, while occupancy factors and atomic displacement parameters should be known to an accuracy of typically 1% and 10%, respectively…