Dissipative particle dynamics: dissipative forces from atomistic simulation

ABSTRACT

We present a novel approach of mapping dissipative particle dynamics (DPD) into classical molecular dynamics. By introducing the invariant volume element representing the swarm of atoms, we show that the interactions between the emerging Brownian quasiparticles arise naturally from its geometric definition and include both conservative repulsion and dissipative drag forces. The quasiparticles, which are composed of atomistic host solvent rather than being simply immersed in it, provide a link between the atomistic and DPD levels and a practical route to extract the DPD parameters as direct statistical averages over the atomistic host system. The method thus provides the molecular foundations for the mesoscopic DPD. It is illustrated on the example of simple monatomic supercritical fluid demonstrating good agreement in thermodynamic and transport properties calculated for the atomistic system and DPD using the obtained parameters.

KEYWORDS:

• Dissipative particle dynamics
• molecular dynamics
• coarse-graining
• parameters estimation
• DL_POLY

Acknowledgments

All calculations were performed on Hartree Centre's computers. VPS gratefully acknowledges stimulating discussions with Patrick Warren and Dominic Tildesley.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported in part by funding from the Computational Collaborative Project 5 (CCP5) Programme of the Science and Technology Facilities Council.