A method for estimating the interactions in dissipative particle dynamics from particle trajectories
Artikel i vetenskaplig tidskrift, 2009

We introduce a method for determining the functional form of the stochastic and dissipative interactions in a dissipative particle dynamics (DPD) model from projected phase space trajectories. The DPD model is viewed as a coarse graining of a detailed dynamics that displays a clear timescale separation. Based on the Mori-Zwanzig projection operator method we derive a consistency equation for the stochastic interaction in DPD. The consistency equation can be solved by an iterative bootstrapping procedure. Combined with standard techniques for estimating the conservative interaction, our method makes it possible to reconstruct all the forces in a coarse-grained DPD model. We demonstrate how the method works by recreating the interactions in a DPD model from its phase space trajectory. Furthermore, we discuss how our method can be used in realistic systems with finite timescale separation.


A. Eriksson

Göteborgs universitet

Martin Nilsson Jacobi

Chalmers, Energi och miljö, Fysisk resursteori

J. Nyström

Chalmers University of Technology

Kolbjörn Tunström

Chalmers, Energi och miljö

Journal of Physics Condensed Matter

0953-8984 (ISSN)

Vol. 21 art. no. 095401- 095401