Sorry, I forgot to mention that the results or dispersion were obtained using qe.6.3-bkp.
Best On Wed, Mar 13, 2019, 15:04 Prof. Raphael Longuinhos Monteiro Lobato < [email protected]> wrote: > Hi, > > Back on the celldm post (sorry for the six months delay to reply ... I > will bring back some parts to remember): > http://lists.quantum-espresso.org/pipermail/users/2018-October/041418.html > > and > > http://lists.quantum-espresso.org/pipermail/users/2018-October/041419.html > > Previously, I wrote: > +== > ph.x from pre-release q-e-qe-6.3Max reads from outdir unexpected values > for celldm and writes these in the header of .dyn . It leads to > "rescaled" distances in .axsf and polarizability in the dynmat.x out > (omega, IR, Raman tensor and depolarization factor are as expected). > Hand-correcting the .dyn header (correct values for celldm) solves it. > > Tests in v6.2 and 6.2.2 leads to expected results (they read from outdir > the expected values for celldm). ph.x prints wrong celldm while reading > from outdir ... it is not related to io_dyn_mat write_dyn_mat_header ... > also, the .xml files are the same. > +== > > Prof. Giannozzi mentioned that > https://gitlab.com/QEF/q-e/commit/9a579539b65bd1502d1f28747e483a1d1059f5f8 > > could have solved the issue. Maybe I'm missing something, but it appears > it did not. > > The issue on the celldm can lead to other unexpected differences on > post-processing the dyn. > > In my case, the high-frequency (low frequency is okay) phonon dispersion > near Gamma calculated with the original (wrong) celldm values and the > ones using hand-correcting values are somewhat different. As example, > the high-frequency LO mode obtained with the wrong cell_dm seems > quadratic (or some d^2f/dk^2 >0 dependency) like using no LR > electrostatics, while it becomes linear-like (I would expect some thing > like that) when using the correct cell_dm. It is show in the images in > appended. Also, there are some "discontinuities" in the branches I not > used to see on results. Also, there are some extra inflection points in > the region I show in the graphs that I would not expect (these appears > using no LR electrostatics). > > Note: The system is expected to be polar semiconductor. In the graphs nq > 07x07x01 and 14x14x01 uses nk is 14x14x1 (spacing of ~0.03*2pi/A). > Later, I used both nk and nq of 16x16x01. Orange diamonds are direct 2D > DFPT calculations (nk 14x14x01 or 16x16x01 leads to identical results in > these direct 2D DFPT calculations). The highest frequency modes from > direct 2D DFPT and from interpolation of dynmat are some what different > (maybe the interpolation is not converged). Data with cell_dm corrected > values are also indicated. > > I will repeat all these using those versions I reported correctly > reading cell_dm values. > > Hope all it is not a "false alarm" (some unnoticed error of my part). > Sorry bring problems, not solutions. > > Best, > > -- > Associate Professor Raphael Longuinhos Monteiro Lobato > CV: http://lattes.cnpq.br/1475483971471395. > Research Group site: http://jenainassoares2.wixsite.com/nanomat > (Portuguese only - English version on the way) > Departamento de Fisica, Universidade Federal de Lavras > Av. Dr. Silvio Menicucci 1001, bairro Kenedy > Post office box 3037 > 37200-000 - Lavras, MG, Brazil > >
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