<div dir="ltr">Hi, <div><br></div><div>Thank you for the suggestion. This contributed to reducing the noise on the forces, and MAE's are now ~ 30% smaller. However, I still observe almost similar performances for MOLOPT basis sets (from DZVP-MOLOPT-SR to TZV2P-MOLOPT, vs. TZV2PX-MOLOPT). In fact, the MAE is even slightly smaller for the smallest, short-range version of DZVP-MOLOPT. Could that be a symptom of over-completeness of basis sets including diffuse functions for this system? </div><div><br></div><div>best, </div><div>Arthur</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">Le mer. 16 juin 2021 à 10:56, <<a href="mailto:hut...@chem.uzh.ch">hut...@chem.uzh.ch</a>> a écrit :<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Hi<br> <br> I to be sure that you don't pick up basis set dependent numerical noise<br> I would suggest to use a more strict eps_default value, e.g. 1.E-14.<br> <br> regards<br> <br> Juerg Hutter<br> --------------------------------------------------------------<br> Juerg Hutter Phone : ++41 44 635 4491<br> Institut für Chemie C FAX : ++41 44 635 6838<br> Universität Zürich E-mail: <a href="mailto:hut...@chem.uzh.ch" target="_blank">hut...@chem.uzh.ch</a><br> Winterthurerstrasse 190<br> CH-8057 Zürich, Switzerland<br> ---------------------------------------------------------------<br> <br> -----<a href="mailto:cp...@googlegroups.com" target="_blank">cp...@googlegroups.com</a> wrote: -----<br> To: "cp2k" <<a href="mailto:cp...@googlegroups.com" target="_blank">cp...@googlegroups.com</a>><br> From: "Arthur France-Lanord" <br> Sent by: <a href="mailto:cp...@googlegroups.com" target="_blank">cp...@googlegroups.com</a><br> Date: 06/06/2021 12:01PM<br> Subject: [CP2K:15521] Poor force convergence wrt basis set size<br> <br> Hi, <br> <br> I'm currently testing atomic force convergence with respect to basis set size, for a crystalline polymorph of sulfur (an array of cyclic S8 molecules). I've tested both standard GTH basis sets (DZVP to QZV2P compared to QZV3P), and MOLOPT (DZVP-MOLOPT-SR to TZV2P-MOLOPT compared to TZV2PX-MOLOPT). I'm observing a slow or poor convergence behavior, which can be seen in these two plots (MAE : mean absolute error, MAPE : mean absolute percentage error, both only computed on the x components of the forces): <br> <br> GTH basis sets: <br> <br> <br> MOLOPT basis sets (the TZV2P-MOLOPT/QZV3P panel is just shown here for comparison) : <br> <br> <br> In particular, TZVP-MOLOPT performs slightly better than TZV2P-MOLOPT..? I'm using a high energy cutoff (2500 Ry and a REL_CUTOFF of 100 Ry), and a rather tight SCF convergence criterion (1.0e-7) with the OT method. Convergence in the SCF is achieved rather fast. <br> <br> Are these errors expected? I was trying to reproduce something similar from what ccan be seen in <a href="https://arxiv.org/pdf/1409.4527.pdf" rel="noreferrer" target="_blank">https://arxiv.org/pdf/1409.4527.pdf</a> (figures 1 and 2), but didn't expect such high relative errors. The configuration I'm using is from a molecular dynamics run to obtain non-zero forces. I'm including a cp2k input file to reproduce the QZV3P calculation. <br> <br> many thanks, <br> Arthur<br> <br> <br> -- <br> You received this message because you are subscribed to the Google Groups "cp2k" group.<br> To unsubscribe from this group and stop receiving emails from it, send an email to <a href="mailto:cp2k%2Bun...@googlegroups.com" target="_blank">cp...@googlegroups.com</a>.<br> To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/8d3ba5a1-9d0f-4dfe-8426-df09318745a9n%40googlegroups.com" rel="noreferrer" target="_blank">https://groups.google.com/d/msgid/cp2k/8d3ba5a1-9d0f-4dfe-8426-df09318745a9n%40googlegroups.com</a>.<br> <br> <br> [attachment "cp2k.inp" removed by Jürg Hutter/at/UZH]<br> [attachment "<a href="http://geometry.xyz" rel="noreferrer" target="_blank">geometry.xyz</a>" removed by Jürg Hutter/at/UZH]<br> <br> -- <br> You received this message because you are subscribed to a topic in the Google Groups "cp2k" group.<br> To unsubscribe from this topic, visit <a href="https://groups.google.com/d/topic/cp2k/-TXuRXyRtxs/unsubscribe" rel="noreferrer" target="_blank">https://groups.google.com/d/topic/cp2k/-TXuRXyRtxs/unsubscribe</a>.<br> To unsubscribe from this group and all its topics, send an email to <a href="mailto:cp2k%2Bun...@googlegroups.com" target="_blank">cp...@googlegroups.com</a>.<br> To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/OF98A1FDDF.1A7050A2-ONC12586F6.003111C8-C12586F6.003111CA%40lotus.uzh.ch" rel="noreferrer" target="_blank">https://groups.google.com/d/msgid/cp2k/OF98A1FDDF.1A7050A2-ONC12586F6.003111C8-C12586F6.003111CA%40lotus.uzh.ch</a>.<br> </blockquote></div>