Re: [ESPResSo-users] time dependent force

[Axel Arnold]

On Wednesday 20 July 2011 16:02:41 Jiajia Zhou wrote:
> Thanks for the reply. I would like to change the force every single
> time step. To do this in the tcl level, I think the force are
> calculated twice for every time step (am I correct?), so I can save
> some time by implementing in the c level.

Hi,

no, the forces are normally calculated only once per time step, but twice used 
in the propagation. Nevertheless, if you have e.g. a periodically oscillating 
force, you definitely want to implement it as an constraint.

Btw, if your external potential is not very exotic, such as e.g. a simple 
sinusoidal potential sin(kx + wt) or so, it would be nice if you could send us 
the code for integration with the next release, since that might be of general 
interest.

Axel

-- 
JP Dr. Axel Arnold
ICP, Universität Stuttgart
Pfaffenwaldring 27
70569 Stuttgart, Germany
Email: address@hidden
Tel: +49 711 685 67609