Name : Benoît CHAMPAGNE
Affiliation : University of Namur, Belgium
Email : firstname.lastname@example.org
Name :Michael SPRINGBORG
Affiliation : University of Saarland, Germany
Email : email@example.com
Linear and non-linear responses to electromagnetic fields are of significant importance both in the characterization of materials and in manipulating fields. Theoretical studies of those are, however, hampered by several important aspects:
- For crystalline systems, the presence of even static fields destroys the translational symmetry. First recently, appropriate theoretical methods for the calculation of the electronic response to those fields have been developed, but the computational approaches have not yet reached a mature level.
- Structural responses (including the vibrational and zero-point vibrational contributions) to the field are rarely determined although these may in some cases be dominating.
- The role of the boundaries of the samples and how these can be treated has not yet been completely clarified.
- For molecular systems, large non-linear responses are interesting which often are found for systems with a small energy gap between occupied and unoccupied orbitals. Exactly these systems are difficult to treat theoretically. They also raise the question of describing resonant or near-resonant responses.
- The presently used approximate functionals within density-functional theory are often particularly inaccurate when calculating higher-order responses to the fields for larger molecules. The precise reason behind this has not yet been clarified completely and reliable functionals for a broad range of compounds and structures are still needed.
- Precise relations between response properties on the one hand and structure and stoichiometry of molecular systems on the other side have hardly been developed, although these will be very helpful in technological applications. This includes the assessment of the potential of compounds going beyond the push-pull-π-conjugated system paradigm, i.e. organometallic compounds, electrides, metal-organic frameworks, open-shell systems, …
These issues shall be discussed by the participants at the symposium.