Dissipative timescales from coarse-graining irreversibility

Coarse graining and scaling in dissipative particle dynamics.

Dissipative particle dynamics (DPD) is now a well-established method for simulating soft matter systems. However, its applicability was recently questioned because some investigations showed an upper coarse-graining limit that would prevent the applicability of the method to the whole mesoscopic range. This article aims to re-establish DPD as a truly mesoscopic method by analyzing the problems ...

Coarse graining from coarse-grained descriptions.

We present a generalization of Zwanzig's method of projection operators to the case where the underlying dynamics is not deterministic. The method allows us to perform a coarse graining of an already coarse-grained level of description in which fluctuations are important. The initial level of description is described by a Fokker-Planck equation and, under suitable approximations, the final slow...

Coarse graining

Multiscale simulations For nearly all systems of interest to us, the most transferrable and fundamental description of matter is one that invokes quantum mechanics. At the highest level of accuracy, this amounts to solving Schrodinger’s equation for all of the subatomic particles in a system. Computationally, many approximations need to be made in order to use ab initio methods, and even these ...

Predictive coarse-graining

Brute-force molecular dynamics simulations are limited by the exuberant number of degrees of freedom and the relatively small time-steps. As a result, only relatively small assemblies of molecules over small time spans are accessible with current and foreseeable computational capabilities. In order to overcome this limitation, coarse-grained models have been proposed which employ a much smaller...

Shape-Based Coarse Graining