<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="EN-US" link="blue" vlink="purple"> <div class="WordSection1"> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Hi Michael<o:p></o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">you can also try to reduce EPS_DEFAULT to 1.0E-12 or less for a better numerical accuracy.<o:p></o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">HTH<o:p></o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p> <p class="MsoNormal"><span style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D">Matthias</span><span lang="DE-CH" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p></o:p></span></p> <p class="MsoNormal"><span lang="DE" style="font-size:11.0pt;font-family:"Calibri",sans-serif;color:#1F497D"><o:p> </o:p></span></p> <div style="border:none;border-left:solid blue 1.5pt;padding:0cm 0cm 0cm 4.0pt"> <div> <div style="border:none;border-top:solid #E1E1E1 1.0pt;padding:3.0pt 0cm 0cm 0cm"> <p class="MsoNormal"><b><span lang="DE" style="font-size:11.0pt;font-family:"Calibri",sans-serif">Von:</span></b><span lang="DE" style="font-size:11.0pt;font-family:"Calibri",sans-serif"> cp...@googlegroups.com <...@googlegroups.com> <b>Im Auftrag von </b>Michael Fischer<br> <b>Gesendet:</b> Mittwoch, 23. Juni 2021 15:34<br> <b>An:</b> cp2k <...@googlegroups.com><br> <b>Betreff:</b> [CP2K:15615] Energy oscillations in vdW-DF calculations<o:p></o:p></span></p> </div> </div> <p class="MsoNormal"><o:p> </o:p></p> <p class="MsoNormal">Dear CP2K community,<br> <br> I am seeing a somewhat strange behaviour in CP2K calculations using vdW-DF functionals (version 7.1): Within one SCF cycle, the calculation sometimes reaches a point where it jumps back and forth between different energy values. Such behaviour is illustrated in a portion of a log file appended to this message. This calculation used the vdW-DF-b86r functional, but I have seen the same behaviour with other vdW-DF functionals. <br> I should add the following points:<br> 1) The compound under consideration, a zeolite with an adsorbed molecule, contains only main group elements (Si, O, C, H, N).<br> 2) Analogous calculations using DFT-D methods (like PBE-D3) show no convergence issues whatsoever.<br> 3) A change of preconditioner (FULL_ALL/FULL_KINETIC) seems to affect the behaviour, but does not resolve the issue.<br> <br> I should also note that I tested the "CUTOFF" parameter within &XC &vdW_POTENTIAL &NON_LOCAL part of the input and found that it should be increased with regard to the default setting to get converged adsorption energies (I use 400 Ry).<br> <br> Any help or suggestions would be highly appreciated.<br> Best regards,<br> Michael<br> <br> Portion of output - oscillations start in the 8th iteration<o:p></o:p></p> <div> <p class="MsoNormal"> Step Update method Time Convergence Total energy Change<o:p></o:p></p> </div> <div> <p class="MsoNormal"> ------------------------------------------------------------------------------<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 1 OT DIIS 0.15E+00 5.0 0.00004571 -5301.9144127012 -5.30E+03<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 2 OT DIIS 0.15E+00 2.4 0.00001858 -5301.9158989932 -1.49E-03<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 3 OT DIIS 0.15E+00 2.4 0.00001214 -5301.9161596822 -2.61E-04<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 4 OT DIIS 0.15E+00 2.5 0.00000142 -5301.9161913868 -3.17E-05<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 5 OT DIIS 0.15E+00 2.4 0.00000043 -5301.9161930782 -1.69E-06<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 6 OT DIIS 0.15E+00 2.4 0.00000011 -5301.9161943445 -1.27E-06<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 7 OT DIIS 0.15E+00 2.4 0.00000005 -5301.9161967775 -2.43E-06<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 8 OT DIIS 0.15E+00 2.4 0.00000001 -5301.9161955633 1.21E-06<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 9 OT DIIS 0.15E+00 2.4 4.0079E-09 -5301.9161967782 -1.21E-06<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 10 OT DIIS 0.15E+00 2.4 1.7554E-09 -5301.9161955634 1.21E-06<o:p></o:p></p> </div> <div> <p class="MsoNormal"> 11 OT DIIS 0.15E+00 2.4 6.2727E-10 -5301.9161967782 -1.21E-06<o:p></o:p></p> </div> <div> <p class="MsoNormal"><o:p> </o:p></p> </div> <p class="MsoNormal">-- <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+unsu...@googlegroups.com">cp2k+unsu...@googlegroups.com</a>.<br> To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/45540fc6-9eb6-4a4b-91e0-037e3e918eaen%40googlegroups.com?utm_medium=email&utm_source=footer"> https://groups.google.com/d/msgid/cp2k/45540fc6-9eb6-4a4b-91e0-037e3e918eaen%40googlegroups.com</a>.<o:p></o:p></p> </div> </div> </body> </html>