Dear All,
Just a quick check before I open a bug report. In my understanding the friction coefficient in the Langevin thermostat is supposed to represent
$\zeta = 6 \pi \eta R$
and therefore, the diffusion coefficient in LD should not depend on the mass of the particle. However, in ESPResSo, the behavior is different, see attached MSD.png. Is this because we choose a different way to define the input parameter for the Langevin thermostat? I did not find anything on it in the UG, so I think the ESPResSo behavior is wrong -- but if anyone can come up with a good argument as to why it should be this way, I'm listening.
If such fundamental things are broken, we should check the rotational diffusion, and other simple aspects of ESPResSo as well.
MSD.png