Quantum Crystallography §

Overview & Synopsis

Switzerland. § Dedicated to Prof. Louis J. Massa on the occasion of his 75 th birthday and to Prof. Dylan Jayatilaka on the occasion of his 50 th birthday in recognition of their pioneering contributions to the field of X-ray quantum crystallography. Abstract Approximate wavefunctions can be improved by constraining them to reproduce observations derived from diffraction and scattering experiments. Conversely, charge density models, incorporating electron-density distributions, atomic positions and atomic motion, can be improved by supplementing diffraction experiments with quantum chemically calculated, tailor-made electron densities (form factors). In both cases quantum chemistry and diffraction/scatterings experiments are combined into a single, integrated tool. The development of quantum crystallographic research is reviewed. Some results obtained by quantum crystallography illustrate the potential and limitations of this field. 2