Toon Verstraelen (Center for Molecular Modeling, Ghent University, Belgium) donnera un séminaire le lundi 30 mai 2016 à 15h intitulé :
A new framework for ab initio polarizable force fields
Attention : suite au déménagement de PHENIX, ce séminaire aura lieu Tour 32-42, Salle 101 (1er étage).
Résumé
Even with the advent of ab-initio molecular dynamics simulations, force fields (FFs) are still the only feasible models to perform many-nanosecond atomistic simulations of extended molecular systems. An FF approximates the potential energy felt by the nuclei as a sum of many terms with a low computational cost. For the majority of force-field simulations, the accuracy of noncovalent interactions is essential. When chemical moieties interact noncovalently, they also perturb each other’s electron density, leading to an enhanced attraction that overcomes the cost of the perturbation. Polarizable force fields (PFFs) try to describe explicitly such density deformations and the associated interaction energy. It is generally accepted that a PFF is required to obtain an accurate and physically sensible force field. Despite significant efforts over the past decades, it remains non-trivial to construct a PFF for a given molecular system of interest. In this presentation, a new PFF formalism will be introduced that is firmly based on electronic structure theory : Atom-Condensed Kohn-Sham DFT, approximated to second order (ACKS2). This model includes unambiguous definitions of the PFF parameters, such that they can be derived directly from an electronic wavefunction. Several examples will be discussed to illustrate the benefits of the ACKS2 model.
