Molecular simulation is a powerful tool to understand and predict various physicochemical

processes, such as the binding of a ligand in an enzyme or the reaction mechanism at the active site

of a catalyst. The dispersion interaction, an attractive force between all forms of matter due to longrange

contributions to the electron correlation energy, often plays an important role in such

simulations. However, its accurate and efficient computation is still an ongoing challenge.

The goal of this project is to develop a new computational model for long-range correlation

energies, which include dispersion interactions. This new model is a unified framework

encompassing recent theoretical developments by both PIs: the many-body dispersion method

(developed by A. Tkatchenko) and the atom-condensed Kohn-Sham model (proposed by T.

Verstraelen). The main novelty is that the new model treats atomic monopole fluctuations on an

equal footing with more standard fluctuating dipoles, for the computation of the long-range

correlation energy.

Our new model may have a substantial impact on two research fields: computational chemistry and

force-field modeling of extended systems, especially for systems with small band gaps. It will be

tested in two different contexts: as a correction for density functional theory and as an energy term

in a force field model. In both cases, systematic benchmarks will be carried out to assess the

practical benefits of the new dispersion model.