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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 16: Modeling and Simulation of Soft Matter II
CPP 16.2: Vortrag
Dienstag, 19. März 2024, 09:45–10:00, H 0106
SiO2-water interface with long-range Charge Equilibration (Qeq) — •Kamila Savvidi1, Ludwig Ahrens-Iwers1, and Robert Meißner1,2 — 1Hamburg University of Technology, Hamburg, Germany — 2Helmholtz-Zentrum Hereon, Geesthacht, Germany
Charge equilibration (Qeq) methods enables the accurate calculation of partial charges in molecular dynamics. The charges are predicted based on the minimization of the electrostatic potential energy, which is in principle calculated up to a cut-off radius. Long-range contributions improve the accuracy of the Coulomb interactions in a system with periodic images, that can advance the prediction of the atomic charges. To this end, we implemented a long-range Qeq scheme in a similar way to the original Qeq method [1] by adding terms with the electronegativity and atomic hardness to the electrostatic energy. The long-range contributions to the Coulomb energy are calculated using Ewald summation and gaussian charges. This method is part of the ELECTRODE package in LAMMPS [2] and shows agreement with the constant potential method when an electric potential is applied. SiO2 and Si electrodes with aqueous electrolytes are studied using the method and compared to results with other Qeq models.
[1] A. Rappe, W. Goddard, Phys. Chem., 95, 3358-3363 (1991) [2] L. Ahrens-Iwers, M. Janssen, S. Tee, R. Meißner, J. Chem. Phys. 157, 084801 (2022)