stream

An MPCD streaming method is required to update the particle positions over time. It is meant to be used in conjunction with an mpcd.Integrator and CollisionMethod. Particle positions are propagated ballistically according to Newton’s equations using a velocity-Verlet scheme for a time Δt\Delta t:

v(t+Δt/2)=v(t)+(f/m)(Δt/2)r(t+Δt)=r(t)+v(t+Δt/2)Δtv(t+Δt)=v(t+Δt/2)+(f/m)(Δt/2)\begin{split} \mathbf{v}(t + \Delta t/2) &= \mathbf{v}(t) + (\mathbf{f}/m)(\Delta t / 2) \\ \mathbf{r}(t+\Delta t) &= \mathbf{r}(t) + \mathbf{v}(t+\Delta t/2) \Delta t \\ \mathbf{v}(t + \Delta t) &= \mathbf{v}(t + \Delta t/2) + (\mathbf{f}/m)(\Delta t / 2) \end{split}

where r and v are the particle position and velocity, respectively, and f is the external force acting on the particles of mass m. For a list of forces that can be applied, see mpcd.force.

Classes