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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 16: Modeling and Simulation of Soft Matter II
CPP 16.8: Talk
Tuesday, March 19, 2024, 11:45–12:00, H 0106
Universal pairwise interatomic van der Waals potentials from dipolar polarizabilities and C6 dispersion coefficients — •Almaz Khabibrakhmanov, Dmitry Fedorov, and Alexandre Tkatchenko — Department of Physics and Materials Science, University of Luxembourg, L-1511 Luxembourg
van der Waals (vdW) interactions play an essential role in determining the structure and properties of many molecular and solid-state systems. Classical force fields used in simulations of large systems still mostly rely on empirical Lennard-Jones (LJ) description of vdW interactions. However, LJ potentials are usually prone to large errors and lack physics behind. Therefore, universal and accurate yet non-empirical vdW potentials are strongly desired. Here, we derive the analytical pairwise vdW-QDO potential between atoms, which depend just on two non-bonded atomic parameters: static dipole polarizability α1 and dispersion coefficient C6. This makes our potential universal, i.e. applicable to all chemical elements.
Our vdW-QDO potential, based on the coarse-grained quantum Drude oscillator (QDO) model for electronic response, shows excellent accuracy for noble-gas dimers against state-of-the-art ab initio and analytical methods. In addition, we demonstrate that the vdW-QDO potential can accurately describe group II atomic dimers. We also apply the vdW-QDO potential to small organic molecules and layered materials. We show that the overbinding error increases with the system size, which emphasizes the growing importance of many-body effects in the extended systems.
Keywords: van der Waals forces; molecular interactions; atomistic simulations