SIG-02 Quantum Crystallography

SIG-02 Scope and Objectives

The special interest group brings together experimentalists, computationalists and theoreticians studying all aspects of electronic charge, spin and momentum distributions in atoms, molecules and condensed matter. Its main objectives are to further the activities of the scientists in their respective fields, to integrate concepts from the many experimental methodologies, from theory and computation, into a coherent understanding of spin, charge and momentum densities and to promote the application of this understanding in the physics, chemistry and biology communities.

The SIG intends to cooperate closely with the IUCr commission in the same field.

At present the following topics play an important role in activities of SIG-02:

  • Crystallographic studies: interaction density including hydrogen bonds, topological analysis of the charge density, total electrostatic potential.
  • Analysis of diffraction data by multipole refinement and maximum entropy methods.
  • Theory and computation of electron densities in large systems, of molecules in the excited state.
  • Compton scattering, magnetic scattering.
  • Electron momentum spectroscopy of amorphous materials, polycrystalline and crystalline membranes and molecules.
  • Neutron and magnetic X-ray scattering.
  • Gamma, e-gamma spectroscopy.
  • Theory and computation of electronic states in molecules and condensed matter.
  • Positron annihilation: heavy fermions, magnetism 2D-ACAR, electronic structure at interfaces, electron-positron correlations.

The field has seen a significant revival induced by the arrival of synchrotron radiation and the development of new detection techniques. Development of these new techniques is considered to be an important aspect by the SIG.