<div dir="ltr">Thank you for your reply,<div> </div><div style>so if the reference change this difference between subsequent references should be added to the delta dipole, since the way it's calculated now the delta dipole is just the difference between the total dipole of a given time step and the previous one, right?</div> <div style> </div><div style>Cheers,</div><div style>Wagner.</div></div><div class="gmail_extra"> <div class="gmail_quote">On Fri, Oct 25, 2013 at 4:37 PM, <<a href="mailto:hut...@pci.uzh.ch" target="_blank">hut...@pci.uzh.ch</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">Yes, the reference (COAC) will change during a MD. Although not 'jump' with the proton, as the oxygens have a much higher weight. Be careful when calculating charged systems! Now the dipole depends on the choice of the reference point. If you change the reference point during a MD also the dipole differences will change! regards Juerg <div class="im"> -------------------------------------------------------------- Juerg Hutter Phone : <a href="tel:%2B%2B41%2044%20635%204491" value="+41446354491">++41 44 635 4491</a> Physical Chemistry Institute FAX : <a href="tel:%2B%2B41%2044%20635%206838" value="+41446356838">++41 44 635 6838</a> University of Zurich E-mail: <a href="mailto:hut...@pci.uzh.ch">hut...@pci.uzh.ch</a> Winterthurerstrasse 190 CH-8057 Zurich, Switzerland --------------------------------------------------------------- -----<a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a> wrote: ----- To: <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a> </div>From: Wagner Homsi Brandeburgo Sent by: <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a> Date: 10/25/2013 03:46PM Subject: Re: [CP2K:4736] difference between wannier total dipole and berry total dipole <div class="HOEnZb"><div class="h5"> Hi, I have another question on the same topic, in the case of using REFERENCE COAC (center of atomic charges) for calculating the total dipole of a protonated water system (bulk water + hydronium), if I understood it correctly the reference would be at the sum of the nuclear charges, I was wondering if the reference would then jump together with the proton as it hops from one water molecule to the next. Cheers, Wagner. On Fri, Oct 25, 2013 at 2:56 PM, <<a href="mailto:hut...@pci.uzh.ch">hut...@pci.uzh.ch</a>> wrote: Hi Berry phase total dipoles are calculated from the determinant of the exp(-ikr) operator. For the Wannier total dipole first localized orbitals are calculated. Then the exp(-ikr) operator matrices are transformed into this new basis. Finally, the determinant is approximated by the product of the diagonal elements. This allows to sparate the dipole into molecular contributions. The two ways of calculation should give very similar total dipoles. Are you sure that you compare values with the same units? There is also the problem of 'branch', meaning that the calculated dipole is given +/- 2Pi/L. regards Juerg Hutter -------------------------------------------------------------- Juerg Hutter Phone : <a href="tel:%2B%2B41%2044%20635%204491" value="+41446354491">++41 44 635 4491</a> Physical Chemistry Institute FAX : <a href="tel:%2B%2B41%2044%20635%206838" value="+41446356838">++41 44 635 6838</a> University of Zurich E-mail: <a href="mailto:hut...@pci.uzh.ch">hut...@pci.uzh.ch</a> Winterthurerstrasse 190 CH-8057 Zurich, Switzerland --------------------------------------------------------------- -----<a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a> wrote: ----- To: <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a> From: labicia Sent by: <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a> Date: 10/24/2013 10:54AM Subject: [CP2K:4726] difference between wannier total dipole and berry total dipole Good morning! We are kind of new on this subject: may somebody tell us in a few words the difference between the wannier total dipole and berry total dipole. Or at least give us some reference to document ourselves? We are simulating a periodic bulk of methane. Are both methods suitable for this kind of system? The trend of the wannier total dipole and berry total dipole are almost the same, apart for a rescaling factor (total_wannier = 4.5 * total_berry + K), with K a constant. Thank you very much, and be patient if the question is a bit trivial, Marco and Andrea -- 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="mailto:cp2k%2Bun...@googlegroups.com">cp2k+uns...@googlegroups.com</a>. To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>. Visit this group at <a href="http://groups.google.com/group/cp2k" target="_blank">http://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/groups/opt_out" target="_blank">https://groups.google.com/groups/opt_out</a>. -- 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="mailto:cp2k%2Bun...@googlegroups.com">cp2k+uns...@googlegroups.com</a>. To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>. Visit this group at <a href="http://groups.google.com/group/cp2k" target="_blank">http://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/groups/opt_out" target="_blank">https://groups.google.com/groups/opt_out</a>. -- 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="mailto:cp2k%2Bun...@googlegroups.com">cp2k+uns...@googlegroups.com</a>. To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>. Visit this group at <a href="http://groups.google.com/group/cp2k" target="_blank">http://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/groups/opt_out" target="_blank">https://groups.google.com/groups/opt_out</a>. -- 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="mailto:cp2k%2Bun...@googlegroups.com">cp2k+uns...@googlegroups.com</a>. To post to this group, send email to <a href="mailto:cp...@googlegroups.com">cp...@googlegroups.com</a>. Visit this group at <a href="http://groups.google.com/group/cp2k" target="_blank">http://groups.google.com/group/cp2k</a>. For more options, visit <a href="https://groups.google.com/groups/opt_out" target="_blank">https://groups.google.com/groups/opt_out</a>. </div></div></blockquote></div> </div>