Ciao Nicola, I agree that 'time-to-accurate-solution' is the goal. However, when you have a variable as in Vasp
PRECFOCK= Low | Medium | Fast | Normal | Accurate that allows you to do a HF calculation in 10 hours if PREFOCK=Low and in an infinite time if PREFOCK=Accurate, I see the time saving part but the accuracy can be hardly tested. And it makes also hard to do a comparison of performance and results with other codes. Best, Dario On Fri, Sep 9, 2016 at 11:55 AM, Nicola Marzari <[email protected]> wrote: > On 09/09/2016 11:37, dario rocca wrote: > > -If you changed the default values of some variables such as Precfock or > > Nkred in Vasp the computational parameters are not anymore the same in > > Vasp and QE. > > > Ciao Dario, > > > all true, but at the end what counts for a expert in DFT but not in > computational implementations is "time-to-accurate-solution". > > This latter requires time in itself to establish (i.e. what are the > parameters > that give me a converged result - say, for non symmetric configurations, > with forces that are converged to .XXX eV/A), but for a DFT > scientist that is a user of codes, rather than a developer of codes, > the question above (let's call it TASK "time-to-accurate-solution > knowing own CPU budget") is a very important one. > > nic > > > ---------------------------------------------------------------------- > Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL > Director, National Centre for Competence in Research NCCR MARVEL, EPFL > http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum >
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