[gpaw-users] odd SCF convergence behavior

[Ask Hjorth Larsen]

Hi

On Mon, 25 Oct 2010, Nichols A. Romero wrote:

> Hi,
>
> Here is the input file in question.
> http://en.pastebin.ca/1973390
>
> The SCF cycle is well-behaved at 64 MPI tasks,
> http://en.pastebin.ca/1973391
>
> but is poorly behaved at 32 MPI tasks.
> http://en.pastebin.ca/1973392
>
> Is there a simple way to explain this difference?
>
> This behavior is present irregardless of using
> GS or Jacobi for the poisson solver?

Seems to me that they are both performing a bit 'randomly', one of them 
just happens to converge by chance.  What happens if you use 100 more 
empty bands?

As for things behaving a bit differently depending on parallelization: It 
has been like always (or a very long time), and I'm not sure why.  Does 
anyone know?  It seems to be more than just numerical noise.

Regards
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