On Tue, Aug 29, 2017 at 7:30 AM, Prasenjit Ghosh <[email protected]> wrote:
Paolo, is there some quick fix for the bug? > no, it's a tricky bug. Or maybe there is one: in my tests, the problem seems to disappear if you replace your structure (lattice only, positions are ok) &system ibrav= 0 , celldm(1)= 8.81679607, ... / CELL_PARAMETERS (alat) 0.999861009 -0.000000000 -0.000000000 -0.499930505 0.865905034 -0.000000000 -0.000000000 -0.000000000 3.428582875 with the equivalent structure &system ibrav= 4 , celldm(1)= 8.8155706147, celldm(3)=3.42905948, ... / Why, I don't know Paolo > With regards, > > Prasenjit > > On 28 August 2017 at 21:17, Paolo Giannozzi <[email protected]> wrote: > >> There is a problem with reduced-cutoff calculations (using ecutfock < >> 4*ecutwfc) and k-points. Thank you for reporting this >> >> Paolo >> >> On Mon, Aug 28, 2017 at 8:33 AM, Prasenjit Ghosh <[email protected] >> > wrote: >> >>> Dear all, >>> >>> We are doing calculations for my system (PbI2) with hybrid functionals >>> (using the ACE algorithm) and norm conserving pseudopotentials. Presently >>> we are performing this calculations using scalar relativistic >>> non-conserving pseudopotentials for Pb and I. The pseudopotentials have >>> been generated by me using PBE functionals. I have tested these (at the >>> level of GGA) and it can reproduce well the lattice parameters and >>> electronic bandstructure of a range of different compounds (from metallic >>> Pb to ionic PbI2 and CsPbBr3). >>> >>> When we perform the hybrid calculations using GAU-PBE, we find that the >>> total energy differs when we use 1 core and 4 cores. The energy difference >>> is about 0.23 Ry. However, for both the cases, the standard GGA-PBE >>> calculations give same results (total energy). Even the band gap with >>> GAU-PBE (using 1 and 4 cores) are same. A look into the output file >>> suggests that the difference comes from >>> -averaged Fock potential + Fock energy. >>> >>> Since I have generated the pseudopotential, I thought that there might >>> be some issue with this. Hence to cross check, I downloaded the >>> normconserving pseudopotentials for Pb and I from >>> http://theossrv1.epfl.ch/Main/Pseudopotentials (pbe.0.3.1.tgz). For >>> these two pseudopotentials also the total energies (1 core vs 4 cores) >>> differ. The input files, pseudopotential files and the output files can be >>> downloaded from the link given below: >>> >>> http://www.iiserpune.ac.in/~pghosh/QE/ >>> >>> These results are reproducible on different machines, using different >>> compilers (eg. gfortran vs intel). >>> >>> I think that there is a bug in the code, particularly the part where the >>> contributions to total energy from EXX is collected. If the developers can >>> suggest where exactly to look for in the code, I can give it a try to sort >>> it out. >>> >>> With regards, >>> >>> Prasenjit. >>> >>> -- >>> PRASENJIT GHOSH, >>> IISER Pune, >>> Dr. Homi Bhabha Road, Pashan >>> Pune, Maharashtra 411008, India >>> >>> Phone: +91 (20) 2590 8203 <+91%2020%202590%208203> >>> Fax: +91 (20) 2589 9790 <+91%2020%202589%209790> >>> >>> _______________________________________________ >>> Pw_forum mailing list >>> [email protected] >>> http://pwscf.org/mailman/listinfo/pw_forum >>> >> >> >> >> -- >> Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, >> Univ. Udine, via delle Scienze 208, 33100 Udine, Italy >> Phone +39-0432-558216 <+39%200432%20558216>, fax +39-0432-558222 >> <+39%200432%20558222> >> >> >> _______________________________________________ >> Pw_forum mailing list >> [email protected] >> http://pwscf.org/mailman/listinfo/pw_forum >> > > > > -- > PRASENJIT GHOSH, > IISER Pune, > Dr. Homi Bhabha Road, Pashan > Pune, Maharashtra 411008, India > > Phone: +91 (20) 2590 8203 <+91%2020%202590%208203> > Fax: +91 (20) 2589 9790 <+91%2020%202589%209790> > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
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