<div dir="ltr"><div>Hi all,</div><div> </div><div>I see that some SE codes do use the minimum image convention. Is the coulombic cutoff one of these, or can the cutoff be larger than one half of the cell length?</div><div> </div><div>Thanks, </div><div>Austin</div><div> </div> On Monday, May 23, 2016 at 6:19:29 AM UTC-6, Guilherme da Silva wrote:<blockquote class="gmail_quote" style="margin: 0;margin-left: 0.8ex;border-left: 1px #ccc solid;padding-left: 1ex;"><div dir="ltr">Hi, Thanks for answering so fast! regards, Guilherme Em segunda-feira, 23 de maio de 2016 08:51:04 UTC-3, jgh escreveu:<blockquote class="gmail_quote" style="margin:0;margin-left:0.8ex;border-left:1px #ccc solid;padding-left:1ex">Hi In almost all parts of the program (exceptions are some DFTB and SE codes, and maybe HFX) CP2K does not use the minimum image convention. It is save to use interaction ranges that are larger than the simulation box. regards Juerg -------------------------------------------------------------- Juerg Hutter Phone : ++41 44 635 4491 Institut für Chemie C FAX : ++41 44 635 6838 Universität Zürich E-mail: <a rel="nofollow">h...@chem.uzh.ch</a> Winterthurerstrasse 190 CH-8057 Zürich, Switzerland --------------------------------------------------------------- -----<a rel="nofollow">c...@googlegroups.com</a> wrote: -----To: cp2k <<a rel="nofollow">c...@googlegroups.com</a>> From: Guilherme da Silva Sent by: <a rel="nofollow">c...@googlegroups.com</a> Date: 05/23/2016 01:42PM Cc: <a rel="nofollow">j...@science.ru.nl</a> Subject: [CP2K:7782] Re: R_CUTOFF vdWaals pair potential Hi, I know that this one is a bit too old, but I have a similar doubt. I think he argues about the possibility of high r_cutoff values to violate the minimum-image convention. Is that simply not true? And if it does violate, have anyone some answer about what would be worse: to violate the mic or to not compute the dispersion correction in an appropriate range? Regards, Em terça-feira, 17 de dezembro de 2013 09:35:30 UTC-2, JanLos escreveu: Dear CP2K developpers, I was wondering about the comment in the section "FORCE_EVAL/DFT/XC/VDW_POTENTIAL/PAIR_POTENTIAL/R_CUTOFF", saying "The cutoff will be 2 times this value". If I stick to the default value of 10.06 Angstrom for this parameter, the cut-off will be 20.12 Angstrom, which is pretty large, but OK. If this is really what is applied, then it would imply that for a cubic simulation box of 20 A cube with periodic boundary conditions, R_CUTOFF should not be set larger than 5.0 Angstrom in order to NOT exceed recommended maximal value for this box size, namely half the box size. Do I see this correctly ? It's just that the comment " The cutoff will be 2 times this value" confuses me, asking myself why this input parameter been defined in this way. By the way, is the minimal image convention applied for the calculation of these interactions ? Regards, Jan Los -- 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 rel="nofollow">cp...@googlegroups.com</a>. To post to this group, send email to <a rel="nofollow">c...@googlegroups.com</a>. Visit this group at <a href="https://groups.google.com/group/cp2k" rel="nofollow" target="_blank" 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" rel="nofollow" target="_blank" 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></blockquote></div>