Quantum crystallography is a branch of crystallography that investigates crystalline materials within the framework of quantum mechanics, with analysis and representation, in position or in momentum space, of quantities like wave function, electron charge and spin density, density matrices and all properties related to them (like electric potential, electric or magnetic moments, energy densities, electron localization function, one electron potential, etc.).
In fact, the scattering of radiation enables mapping the one-electron distribution[2][3][4] or the elements of a density matrix.
This definition mainly refers to studies started in the 1960s and 1970s, when first attempts to obtain wave functions from scattering experiments appeared,[10] together with other methods to constrain a wavefunction to experimental observations like the dipole moment.
[22] In a recent review article, V. Tsirelson[23] gave a more general definition: "Quantum crystallography is a research area exploiting the fact that parameters of quantum-mechanically valid electronic model of a crystal can be derived from the accurately measured set of X-ray coherent diffraction structure factors".
The book Modern Charge Density Analysis offers a survey of the research involving Quantum Crystallography and of the most adopted experimental or theoretical methodologies.