Computing dissipative particle dynamics interactions to render molecular structure and temperature-dependent properties of simple liquids

H Camoglu and T Urbic and G de With and G Kacar, JOURNAL OF MOLECULAR LIQUIDS, 367, 120539 (2022).

DOI: 10.1016/j.molliq.2022.120539

Simulating structural and thermodynamical properties of liquids has always been a challenge. Typical examples of liquids that demonstrate particular structure and properties are water and the low molecular weight alcohols, for which hydrogen bond interactions lead to their distinctive properties, such as cage -like structures and temperature- dependent properties. Modeling these materials at the coarse-grained level is even a bigger challenge due to the loss of atomistic-level interactions. Nevertheless, one is inter-ested in mimicking these typical properties at the coarse-grained level due to the relevance of these sys-tems in complex environments, for which fully atomistic simulations still remain a challenge. In this paper, we introduce a mesoscopic level parameterization of DPD interactions to study the particular structural and thermodynamic properties of liquid water, methanol, ethanol and 1-propanol. The conser-vative repulsive DPD interactions are explicitly computed by a bottom-up parameterization, in which experimental thermodynamics data are used. A previously developed statistical mechanics approach is used to compute the hydrogen bond strength. The transport properties, such as viscosity, and thermody- namical properties, such as isothermal compressibility, are found to agree reasonably well with experi-mental data. Moreover, the structure as characterized by the radial distribution function and angular distributions of three neighboring molecules are in line with the atomistic simulations performed in this work. Furthermore, the temperature-dependency of the repulsive DPD interactions is modeled by incor-porating the experimental isothermal compressibilities at different temperatures. The effect of the tem-perature on the hydrogen bond strengths is considered as well and the structural properties are predicted via the DPD simulations. In general, our work can be viewed as an attempt to model systems by the DPD simulations, where hydrogen bonds play a crucial role. The computed parameterization of DPD interac-tions is believed to pave the way towards extending the current applicability of DPD method to more complex systems. (c) 2022 Elsevier B.V. All rights reserved.

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