Quantum crystallography, a technique for extending the concept of structure

Abstract

A developing area of research concerns a technique for extracting quantum mechanically valid properties from X-ray diffraction experiments. Quantum mechanics and crystallography are joined through the fact that the electron distributions around atoms are the source of X-ray diffraction and electron density distributions are observables that lend themselves readily to quantum mechanical description. Direct contact with the X-ray diffraction data is made by equating the structure factor magnitudes, which are readily obtained from the measured X-ray diffraction intensities with the magnitudes of Fourier transforms of the quantum mechanical description of the electron distribution. The article concerns a further discussion of quantum crystallography and its implications. To create a quantum mechanical model, crystallographic information in the form of atomic positions is used. Since quantum crystallography is applicable to very large structures, methods for handling very large structures are described.