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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 2: Modeling and Simulation of Soft Matter I
CPP 2.9: Vortrag
Montag, 27. März 2023, 12:00–12:15, MER 02
Coarse-grained modelling of liquid-liquid and liquid-gas interfaces — •Jakob Filser1, Harald Oberhofer2, Christoph Scheurer1, and Karsten Reuter1 — 1Fritz-Haber-Institut der MPG, Berlin, Germany — 2Chair for Theoretical Physics VII, University of Bayreuth
Modelling of dielectric interfaces remains a central challenge in computational chemistry. We present a new method to incorporate solvation effects into density-functional theory calculations of organic adsorbates at liquid-liquid and liquid-gas interfaces.
Simulating a large number of solvent molecules explicitly at first-principles level is generally not computationally tractable. We therefore resort to an implicit solvation approach, treating the solvent as a structureless dielectric continuum. Specifically, we advance the multipole-expansion method, in which we model the interface as the boundary of two semi-infinite media with different permittivity. Gauging the limiting behaviour for moving the solute from one bulk medium into the other is straightforward by referencing experimental transfer free energies. Complementary force-field level MD simulations with explicit solvent molecules are used as a reference for the behaviour at the interface. These calculations yield thermal distributions at atomic scale resolution, allowing for a fine assessment of the role of the solvent structure in the adsorption. In our implicit method, we employ a model for the transition of free energy terms, such as the surface tension, between the two media, aimed at reproducing the above mentioned thermal distributions extracted from an atomistic solvent model.