Re: [ESPResSo-users] Periodic boundary condition OIF

[Ivan Cimrak]

Hi Markus,

First, I will give you a simple answer:
If you use streching only (e.g. by "oif_create_template template-id 0
nodes-file NODES.dat triangles-file TRIANLGES.dat ks 0.05"), then the
periodicity will work.

Here comes the longer answer:
stretching forces are implemented in a way that the periodicity is
used in the same way as the original Espresso does. However, the local
area, bending, global area and volume forces are implemented slightly
different: The coordinates of the particles are first folded before
the calculation of the forces. This however means that natural
periodicity of Espresso is broken.

The reason for the folding was that without it it did not work
correctly. This is an issue that is on our TODO list though.


Ivan




On Tue, Jan 20, 2015 at 4:46 PM, Wink, Markus
<address@hidden> wrote:
> Hello everybody,
>
>
>
> if putting point-like particles into a lb-fluid, the periodic boundary
> condition works just fine. Meaning, that when a particle leaves the
> simulation box at one end it enters the box at the other end again. In
> contrast to that, if I use the Object in fluid package, I don’t get that
> behavior. Every time, the extended object reaches the end of the simulation
> box, I get the following error message and no further integration steps are
> performed:
>
>
>
> broken: particles sum 3, id 0, partn 2, bond 2346
>
>
>
> I was wondering if the periodic boundary condition is implemented in the
> oif-package and if: How can I apply/switch on a periodic condition for the
> extended object?
>
>
>
> Thank you very much for your help.
>
>
>
> Greetings
>
>
>
> Markus
>
>
>
>



-- 
Ivan Cimrak
FRI Zilinska Univerzita v Ziline
personal web: http://www.kst.fri.uniza.sk/~icimrak/
cell-in-fluid group: http://cell-in-fluid.fri.uniza.sk