Thanks a lot Nicola and Paolo. Paolo, is there some quick fix for the bug?
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, fax +39-0432-558222 > > > _______________________________________________ > 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 Fax: +91 (20) 2589 9790
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