Re: [ESPResSo] Shear Flow without NEMD

[Olaf Lenz]

Hi!

Vincent Buerger wrote:
> is it possible to apply a shear flow or velocity gradient to a simulation
> box in ESPResSo without making use of the NEMD (non-equilibrium molecular
> dynamics) algorithm?

So far, only the NEMD algorithm to create a shear flow has been 
implemented. One could think of other algorithms to create a shear flow, 
but you would have to implement the required extensions yourself. I 
don't think it should be very complicated.
The question, however, is: why do you want to do that?
The NEMD algorithm is an advanced algorithm that allows to do a shear 
flow simulation at constant temperature. What alternative do you want to 
use?

> For example, can one play with the simulation box boundaries, and move the
> top plate of the simulation box along one coordinate axis?

The problem is that there is no "top plate" in an ESPReSo simulation 
box. The box is periodic in all directions. Even if you would create a 
wall constraint, which is probably what you would think of as a plate, 
it is not suitable for transferring momentum to particles in the box.

Best regards

        Olaf