[Pw_forum] born effective charges

[Paolo Giannozzi]

On Oct 9, 2006, at 16:40 , Vivek Ranjan wrote:

> After the programme prints the dielectric constants, it must calculate
> the born effective charges. With the given computer resources at my
> disposal, it cannot complete this part. So, I must restart the  
> calculation
> from the previous step. I use "recover.true." flag. But it never seems
> to go beyond the dielectric constant calculation part.

there is something I don't understand here. The calculation of the
dielectric response takes something of the order of 3 times the time
needed for the scf calculation on the same system. Once this is
done, the calculation of effective charges takes close to nothing.
What is the part that you cannot complete? Use 'epsil=.true.,
trans=.false. to skip the calculation of phonon modes (which
will take a lot of time if you have a lot of atoms)

Paolo