Grabowsky S Genoni A Bürgi HB 2017 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/scattering 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. https://sonar.ch/global/documents/124494 eng info:eu-repo/semantics/altIdentifier/doi/10.1039/c6sc05504d info:eu-repo/semantics/altIdentifier/pmid/28878872 Chemical science. - 2017 Quantum crystallography. http://purl.org/coar/resource_type/c_6501