Re: [ESPResSo-users] help

[Axel Arnold]

On Monday 18 June 2012, mehdi ezatabadi wrote:
> Hi
> 
> Dear friends
> 
> I have a problem in my simulations. I have lj interaction among two types
> of my particles but also  I should have to force them interact just by the
> nearest particle in the cut off radius.
> For example I have a type A base that in its neighborhood there are lots of
> type T bases. The type A base have to interact by the nearest type T base
> and not to interact by the others. How can I do it by the Espresso ?!
> If anyone have a sample code I will be thanked .
> 
> Regards, Mohammad

Hi,

something like this has not been implemented so far, therefore, there is no 
example piece of code.

Apart from this, it will be quite a challenge to implement, since our force 
calculation relies on Newton's third law. This means in practice, that the 
forces between an A-particle and a T-particle are calculated on either the T- 
or A-particle, but you still need to check the neighborhood of the A particle, 
which means climbing around in the particle structure. At the processor 
boundary, that can be a bit of fun...

The problems can be solved, but this would require quite a bit of low level 
coding from you. If you feel comfortable with coding, I can tell you how to 
get the neighborhood of a particle, plus dealing with the parallelization 
issues.

Regards,
Axel

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