Multi-particle collision dynamics (MPC), also known as stochastic rotation dynamics (SRD), is a particle-based mesoscale simulation technique for complex fluids which fully incorporates thermal fluctuations and hydrodynamic interactions. Coupling of embedded particles to the coarse-grained solvent is achieved through molecular dynamics.
Contents
Method of simulation
The solvent is modelled as a set of
During the streaming step, the coordinates of the particles are updated according to
where
After the streaming step, interactions between the solvent particles are modelled in the collision step. The particles are sorted into collision cells with a lateral size
where
If the structure of the collision grid defined by the positions of the collision cells is fixed, Galilean invariance is violated. It is restored with the introduction of a random shift of the collision grid.
Explicit expressions for the diffusion coefficient and viscosity derived based on Green-Kubo relations are in excellent agreement with simulations.
Simulation parameters
The set of parameters for the simulation of the solvent are:
The simulation parameters define the solvent properties, such as
where
A typical choice for normalisation is
Applications
MPC has become a notable tool in the simulations of many soft-matter systems, including