Re: [ESPResSo-users] Ewald summation

[Olaf Lenz]

Hi!

On 09/14/2011 11:03 AM, Farnoosh Farahpoor wrote:
> Dear Espresso developers I have a question about Ewald method. 
> ewald.c and ewald.h files are included in the src folder of even
> last espresso version but the ewald method is not described in the
> user guide of espresso. Is there any reason for this issue? Is it
> safe to use those files to compute the coulomb force in a periodic
> system?

Yes, there is a reason. The reason is, that the Ewald implementation is
buggy - the forces computed by the Ewald method are simply wrong. So
far, nobody has tried to fix it, even though it is probably just some
small error in the prefactors or the like.

We would be very happy if somebody would fix it...

Olaf

-- 
Dr. rer. nat. Olaf Lenz
Institut für Computerphysik, Pfaffenwaldring 27, D-70569 Stuttgart
Phone: +49-711-685-63607

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