An easy to use, gpu-accelerated all-atom Brownian particle and swimmer simulation framework


Although the main objective of the framework is to provide an easy and user-friendly solution for simulating colloids immersed in a Lennard-Jones fluid, TKMMD is not limited to this purpose. Other feasible applications include binary and confined fluids, liquid-vapour interfaces and glass transitions.


We strive to make the simulation-driven research on Brownian particles and swimmers as easy and straightforward as possible, while simultaneously being able to harness all the processing power modern cuda-enabled GPU-devices can provide.

To this end we developed a highly specialized C++ template library, utilizing all the nifty features of C++11 and CUDA. We further reduced the complexities of writing simulation scripts going hand in hand with low-level C++ templates, by means of a Python-Wrapper focused solely on user-friendliness.
The following example script constructs the initial configuration of a spherical Brownian particle in a LJ-liquid, equilibrates the system, brings the system in a non-equilibrium steady state and subsequently measures a few observables for a specific amount of time.

import tkmmd
sim = tkmmd.Simulation(N=160000)
fluid = sim.setup_lj_fluid(rho=0.835, T=0.75)
colloid = sim.add_spherical_colloid(R=5.1, rho=8,
sim.add_harmonic_trap(colloid, k=2)

equilibration_steps = sim.equilibrate(T=0.75)

boundary = fluid.boundary(center=colloid.pos)


Notable features of the Python-Wrapper include:


Gianmaria Falasco, Richard Pfaller, Andreas P. Bregulla, Frank Cichos, and Klaus Kroy. Exact symmetries in the velocity fluctuations of a hot Brownian swimmer. Phys. Rev. E 94, 030602(R), September 2016 (doi:10.1103/PhysRevE.94.030602)



Responsible for this website’s content and design:
Richard Pfaller
Institut für Theoretische Physik
Universität Leipzig
Brüderstr. 16
D-04103 Leipzig