[Pw_forum] phonon calculation for large system

[Paolo Giannozzi]

On Apr 30, 2009, at 10:13 , Gabriele Sclauzero wrote:

> I think you can use this parallelization level even on a  cluster,
> so that you do not have to do modes and irreps sequentially,
> but you can split  them in concurrently running (multiprocessor)
> jobs so that you-ll have an actual speed-up.

sure, but it is currently not implemented in a MPI framework:
it has to be done "by hand". It isn't difficult to implement it,
using the "image group", though.

> Or are you forced to use a single processor in order to exploit
> this start_q, last_q,... keywords?

no, I don't think so, or if so, it can be easily fixed

Paolo
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Paolo Giannozzi, Democritos and University of Udine, Italy