<div dir="ltr"><div><div><div><div><div><div>Dear all,<br><br></div>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).<br><br></div>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 <br>-averaged Fock potential + Fock energy. <br><br></div>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 <a href="http://theossrv1.epfl.ch/Main/Pseudopotentials" target="_blank">http://theossrv1.epfl.ch/Main/<wbr>Pseudopotentials</a>
(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:</div><div><br></div><div><a href="http://www.iiserpune.ac.in/~pghosh/QE/">http://www.iiserpune.ac.in/~pghosh/QE/</a></div><div><br></div><div>These results are reproducible on different machines, using different compilers (eg. gfortran vs intel).<br><br></div>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.<br><br></div>With regards,<br><br></div>Prasenjit.<br clear="all"><br>-- <br><div class="gmail_signature"><div dir="ltr">PRASENJIT GHOSH,<br>IISER Pune,<br>Dr. Homi Bhabha Road, Pashan<br>Pune, Maharashtra 411008, India<br><br>Phone: +91 (20) 2590 8203<br>Fax: +91 (20) 2589 9790</div></div>
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