Nuclear quantum effects in fullerene-fullerene aggregation in water

Front Chem. 2022 Dec 15:10:1072665. doi: 10.3389/fchem.2022.1072665. eCollection 2022.

Abstract

We studied the effects of the quantum delocalization in space of the hydrogen atoms of water in the aggregation process of two fullerene molecules. We considered a case using a purely repulsive water-fullerene interaction, as such a situation has shown that water-mediated effects play a key role in the aggregation process. This study becomes feasible, at a reduced computational price, by combining the path integral (PI) molecular dynamics (MD) method with a recently developed open-system MD technique. Specifically, only the mandatory solvation shell of the two fullerene molecules was considered at full quantum resolution, while the rest of the system was represented as a mean-field macroscopic reservoir of particles and energy. Our results showed that the quantum nature of the hydrogen atoms leads to a sizable difference in the curve of the free energy of aggregation; that is, that nuclear quantum effects play a relevant role.

Keywords: PMF of aggregation of hydrophobic particles; adaptive resolution simulation (AdResS) method; fullerene; nuclear quantum effects; path integral molecular dynamics.