Dear Narendra, While a PBE calculation requires a single FFT for the density the PBE0 calculation requires N_bands*N_bands FFTs for the co-density. In your case if nspin=1 you would have about 47000 FFTs for a single EXX evaluation. Despite the number of processors, the number of bands might be the bottleneck of your calculation. I don't know if an efficient band parallelization is available for the EXX in QE but it could help. Best, Dario
On Mon, Aug 8, 2016 at 1:39 PM, Narendranath Ghosh <ghosh.nare...@gmail.com> wrote: > Dear Dario > I could not complete my last PBE0 "scf" job containing 434 > atoms (CNT+Fullerene). The job could not stop but still running without > writing any more in the output file. These lines are written in the output > 34 hours ago .I have tried it twice but I found same thing. > > EXX: now go back to refine exchange calculation > > total cpu time spent up to now is 42069.2 secs > > Self-consistent Calculation > > iteration # 1 ecut= 30.00 Ry beta=0.45 > Davidson diagonalization with overlap > > I could not understand what's happening.I have used 24 node with 384 > processors.I have alter ecut, cell length, beta values nothing happened. > > Please suggest any idea....... > > > > On Sun, Aug 7, 2016 at 10:53 AM, dario rocca <roc...@gmail.com> wrote: > >> I will let the MD experts to reply to this question :) >> >> On Sat, Aug 6, 2016 at 2:49 AM, Narendranath Ghosh < >> ghosh.nare...@gmail.com> wrote: >> >>> Dear Dario >>> >>> Thank you very much for your valuable suggestion. As my systems are >>> quite large and require high computational resources , I decided to compare >>> one of my result with that of PBE0. >>> >>> One problem that I am facing now "after successfully optimized the >>> (CNT+Fullerene) systems now I am looking for to get 5 picosecond "md" >>> trajectory". >>> In QE which flags allowed one to get *MD trajectories * *with NVE >>> ensemble. *I find some idea from http://qe-forge.org/piper >>> mail/pw_forum/2009-June/087573.html. But that is not clear to me. >>> >>> Please suggest any idea..... >>> >>> Thank you again >>> >>> *Narendra Nath Ghosh* >>> >>> *Research Associate* >>> >>> *University of Gour Banga* >>> >>> *Department of Computational Physics * >>> >>> *Malda-732102* >>> >>> *India* >>> >>> On Sat, Aug 6, 2016 at 10:48 AM, dario rocca <roc...@gmail.com> wrote: >>> >>>> Dear Narendra, >>>> If you do a PBE calculation with norm-conserving, ultrasoft, and PAW >>>> pseudopotentials very likely you will get very similar results (but it >>>> depends >>>> also on the quality of the pseudopotential, the property under >>>> consideration, etc.). >>>> In the case of PBE0 the type of pseudopotential will have a stronger >>>> effect on the final result. >>>> For purely esthetic reasons, if your previous calculations didn't take >>>> too long you could redo them with norm-conserving pseudopotentials and >>>> confirm that the results are indeed the same. >>>> Otherwise I don't see anything wrong in comparing, for example, a gap >>>> obtained at PBE level with US pseudos and a gap obtained at PBE0 >>>> level with NC pseudos. >>>> Best, >>>> Dario >>>> >>>> >>>> >>>> On Fri, Aug 5, 2016 at 3:44 PM, Narendranath Ghosh < >>>> ghosh.nare...@gmail.com> wrote: >>>> >>>>> Dear Dario >>>>> >>>>> Thank you very much for your support.It works well and some of the >>>>> jobs have been finished successfully. >>>>> >>>>> But one thing in my mind. In my whole calculations , I used PBE with >>>>> ultrasoft pseudopotentials. But to do "scf" calculations with PBE0 >>>>> "hybrid" >>>>> functional I have to use "Norm conserving pseudopotential". So how >>>>> can I compare these two results. >>>>> >>>>> Please suggest any idea..... >>>>> >>>>> Thank you again >>>>> >>>>> *Narendra Nath Ghosh* >>>>> >>>>> *Research Associate* >>>>> >>>>> *University of Gour Banga* >>>>> >>>>> *Department of Computational Physics * >>>>> >>>>> *Malda-732102* >>>>> >>>>> *India* >>>>> >>>>> >>>>> On Thu, Aug 4, 2016 at 2:17 AM, dario rocca <roc...@gmail.com> wrote: >>>>> >>>>>> Dear Narendranath, >>>>>> Your calculation has reached convergence if you read the message "EXX >>>>>> self-consistency reached". >>>>>> You can learn some details about the scf procedure with hybrid >>>>>> functionals in PW/examples/EXX_example. >>>>>> PBE0 and hybrid functional calculations are in general very >>>>>> expensive. I would suggest you run an example to see what to expect. >>>>>> You might also try to perform a calculation on your system with >>>>>> minimal computational parameters (very small cut-off, few/one k-points) >>>>>> just to see that your run can indeed terminate smoothly. Then I would >>>>>> look >>>>>> for a set of parameters which are a good compromise between computational >>>>>> time and the accuracy you need. >>>>>> You might also try to modify the parameter ecutfock to gain some >>>>>> speed. >>>>>> For sure a hybrid functional calculation on a CNT+Fullerene system >>>>>> might be rather challenging. >>>>>> Best, >>>>>> Dario >>>>>> >>>>>> On Wed, Aug 3, 2016 at 11:16 AM, Narendranath Ghosh < >>>>>> ghosh.nare...@gmail.com> wrote: >>>>>> >>>>>>> Dear all >>>>>>> >>>>>>> After optimizing a system "CNT+Fullerene" with >>>>>>> "PBE" I am trying to calculate "scf" calculation with "PBE0" hybrid >>>>>>> functional using NC Pseudopotential. >>>>>>> >>>>>>> In output file I found "*convergence has been achieved in 15 >>>>>>> iterations" *But the job was not finished even after more than one >>>>>>> week. I could not find any mistake in my input. >>>>>>> >>>>>>> >>>>>>> Please suggest any idea. >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Pw_forum mailing list >>>>>>> Pw_forum@pwscf.org >>>>>>> http://pwscf.org/mailman/listinfo/pw_forum >>>>>>> >>>>>> >>>>>> >>>>>> _______________________________________________ >>>>>> Pw_forum mailing list >>>>>> Pw_forum@pwscf.org >>>>>> http://pwscf.org/mailman/listinfo/pw_forum >>>>>> >>>>> >>>>> >>>>> _______________________________________________ >>>>> Pw_forum mailing list >>>>> Pw_forum@pwscf.org >>>>> http://pwscf.org/mailman/listinfo/pw_forum >>>>> >>>> >>>> >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> Pw_forum@pwscf.org >>>> http://pwscf.org/mailman/listinfo/pw_forum >>>> >>> >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> Pw_forum@pwscf.org >>> http://pwscf.org/mailman/listinfo/pw_forum >>> >> >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum@pwscf.org >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > _______________________________________________ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum >
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