[Pw_forum] ion problem

[Stefano de Gironcoli]

The Makov-Payne correction (assume_isolated flag in &electrons) corrects 
for the leading term in the  cluster-backgound interaction .
This should reduce the size of the supercell needed, which should 
however be large and cheched for conergence.
stefano

Cyrille Barreteau wrote:
> Dear all
>
> I have a question related to this problem.
> I am interested in the study of charged clusters.
> If I understand well, due to to the periodicity of the plane wave codes
> one has to substract the correct "background" in order to keep the
> energy from going to infinity..
>
> I would like to compare the energy of clusters with different
> charges -e -2e etc... Do you have some advices to do such calculation?
> Is it necessary to take even larger supercells than for neutral clusters?
>
> thanks in advance
>
>   cyrille
>
>