<div dir="ltr"><div>Dear Juerg,</div><div>Thanks a lot for your feedback -- with this, I will continue to use GAPW, </div><div>exploring also the influence of EPSISO and EPSFIT, and checking the </div><div>PW cutoff convergence when decreasing HARD_EXP_RADIUS.</div><div>Best,</div><div>Maxime </div><div> </div><div> </div> Op maandag 12 november 2018 03:20:32 UTC-5 schreef jgh:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;">Hi there are a few parameters that determine the numerical accuracy of a GAPW calculation. We tried to pick good default values for them, but it is well possible that for certain elements/basis set combinations they do not work. HARD_EXP_RADIUS sets the GAPW atomic sphere radius. The smaller this value the higher the PW cutoff you will need. It shifts the border between the soft and hard part of the basis set. The same is also true for EPSFIT. This parameter sets the accuracy of the fitting of the different densities at the GAPW sphere radius. For heavy elements EPSISO can also be of importance (determines which basis functions are completely within the GAPW sphere). Usually, one can see the sensitivity of a calculation by changing these parameters and then search for stable values. best Juerg Hutter -------------------------------------------------------------- Juerg Hutter Phone : ++41 44 635 4491 Institut für Chemie C FAX : ++41 44 635 6838 Universität Zürich E-mail: <a href="javascript:" target="_blank" gdf-obfuscated-mailto="LFlsSmA4BgAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">hut...@chem.uzh.ch</a> Winterthurerstrasse 190 CH-8057 Zürich, Switzerland --------------------------------------------------------------- -----<a href="javascript:" target="_blank" gdf-obfuscated-mailto="LFlsSmA4BgAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a> wrote: ----- To: "cp2k" <<a href="javascript:" target="_blank" gdf-obfuscated-mailto="LFlsSmA4BgAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a>> From: "Maxime Van den Bossche" Sent by: <a href="javascript:" target="_blank" gdf-obfuscated-mailto="LFlsSmA4BgAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a> Date: 11/10/2018 04:51PM Subject: [CP2K:10927] GAPW convergence for Cu and Ni Dear all, I would like to use the GAPW method in CP2K to study (late) transition metal clusters, as it would offer quite an increase in speed compared to GPW (because GAPW requires less high plane-wave cutoffs for dealing with such "harder" pseudopotentials). I had no problems performing GAPW runs for fifth- and sixth-row elements (Pd, Ag, Pt, Au), but for the fourth-row ones (Ni, Cu), I ran into severe SCF convergence problems (strongly oscillatory behaviour). I managed to create a minimal example, involving just the Cu dimer, where this behaviour is also present (see attached input and output files). In this particular case, the SCF does converge when using the DIRECT_P_MIXING mixing scheme, but this solution is not applicable to my original problem, where I need e.g. Broyden mixing. I then found that lowering the HARD_EXP_RADIUS parameter to 1.2 Bohr radii or below (compared to the default value of 1.512) makes the SCF cycle converge without problems. I realize that the GAPW mode is still a bit more "experimental" compared to GPW, so I'm fine with having to tinker with such parameters, but I wanted to check with you: Does it indeed make sense to you that the default value for HARD_EXP_RADIUS is not appropriate here? Would this e.g. be related to the shorter 3d-orbital radius for Cu compared to Ag-4d and Au-5d? Best regards, Maxime -- You received this message because you are subscribed to the Google Groups "cp2k" group. To unsubscribe from this group and stop receiving emails from it, send an email to <a href="javascript:" target="_blank" gdf-obfuscated-mailto="LFlsSmA4BgAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp2k+uns...@googlegroups.com</a>. To post to this group, send email to <a href="javascript:" target="_blank" gdf-obfuscated-mailto="LFlsSmA4BgAJ" rel="nofollow" onmousedown="this.href='javascript:';return true;" onclick="this.href='javascript:';return true;">cp...@googlegroups.com</a>. Visit this group at <a href="https://groups.google.com/group/cp2k" target="_blank" rel="nofollow" onmousedown="this.href='https://groups.google.com/group/cp2k';return true;" onclick="this.href='https://groups.google.com/group/cp2k';return true;">https://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/d/optout" target="_blank" rel="nofollow" onmousedown="this.href='https://groups.google.com/d/optout';return true;" onclick="this.href='https://groups.google.com/d/optout';return true;">https://groups.google.com/d/optout</a>. </blockquote></div>