Re: [ESPResSo] Restarting a Simulation

[Axel Arnold]

On Tuesday 13 April 2010 00:35:18 Salvador Herrera Velarde wrote:
> Hi Axel,
> Thanks a lot for your answer.
>
> I just have one more question.
>
> If a want to start a new simulation with box length say {30 30 30} and I
> need the coordinates from a previous simulations via:
> $last_configuration.gz" {time box_l npt_p_diff } {id pos type v f
> molecule}. The coordinates in this file (last_configuration.gz) are outside
> of the box size 30 30 30 because of they are unfolded.  So, how ESPResSo
> treats these coordinates in my new box simulation [30 30 30]?

Hi,

since the coordinates are stored as absolute, unfolded coordinates, the 
absolute coordinate will of course be the same, but the folded position inside 
the 30 30 30 box. If you had before a box of size 15x15x15, and a particle 
moved to 20 0 0 (so 5 0 0 in folded coordinates), then, in the new box, it 
will appear at 20 0 0, both folded and unfolded. However, if you put 8 copies 
of your box, shifted to fill the new box, then everything is fine again, since 
there will be a copy at 20+15 0 0, which gets folded to 5 0 0. The only 
problem that can appear is if you would like to fill only 1/8 of your box, 
then of course some particles can be out of the original, smaller periodic 
box.

Many regards,
Axel


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