<div dir="ltr"><div>Hi Rajorshi,</div><div><br></div><div>since you're dealing with a periodic system, I suggest you use the &PERIODIC_EFIELD</div><div>keyword instead of those you indicated. <br></div><div><br></div><div>Best wishes,</div><div>Giuseppe Cassone<br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jul 11, 2022 at 9:02 PM Rajorshi Chattopadhyay <<a href="mailto:rajorshichat@gmail.com">rajorshichat@gmail.com</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div dir="ltr">Hello all,<div><br></div><div>I am trying to do Wannier localisation of liquid water at ambient conditions in a constant external electric field in order to calculate molecular polarizabilities. Accordingly, I extract a few snapshots from the production simulation and do Wannier localisation of these configurations using REFTRAJ. I find that there are two ways of applying electric fields in cp2k, &EXTERNAL_POTENTIAL and &EFIELD. Which of these two can be used here ?</div><div><br></div><div>Since, by using REFTRAJ, I am doing static calculations, I thought that &EXTERNAL_POTENTIAL should be used in my case. Accordingly, I have added the following part in my input script : </div><p style="margin:0px;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><br></span></p><p style="margin:0px;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures">&EXTERNAL_POTENTIAL</span></p> <p style="margin:0px;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>FUNCTION A*X+B*Y+C*Z</span></p> <p style="margin:0px;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>PARAMETERS A B C</span></p> <p style="margin:0px;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>UNITS au_pot au_pot au_pot</span></p> <p style="margin:0px;font-stretch:normal;font-size:11px;line-height:normal;font-family:Menlo;color:rgb(0,0,0)"><span style="font-variant-ligatures:no-common-ligatures"><span> </span>VALUES 0 0 0.001</span></p> <div><span style="color:rgb(0,0,0);font-family:Menlo;font-size:11px"> </span><span style="color:rgb(0,0,0);font-family:Menlo;font-size:11px">&END EXTERNAL_POTENTIAL</span></div><div><br></div><div>Does this apply a constant electric field of magnitude 0.001 au_units in the z direction ?</div><div><br></div><div>I could not find any tutorial where the application of &EXTERNAL_POTENTIAL has been shown. I thank you in advance for your help and suggestions. <br></div><div><div><br></div>-- <br><div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div><font face="Arial, sans-serif"><span style="line-height:16.12px">With Regards,</span></font></div><div><font face="Arial, sans-serif">Rajorshi Chattopadhyay,</font></div><div><font face="Arial, sans-serif">PhD Researcher in Mineralogy/Crystallography,</font></div><div><font face="Arial, sans-serif"><span style="line-height:16.12px">Institut für Geologie und Mineralogie,</span></font></div><div><font face="Arial, sans-serif"><span style="line-height:16.12px">Universität zu Köln, Germany<br></span></font></div><div style="font-size:small"><br></div><div style="font-size:small"><span style="line-height:16.12px;font-size:12.8px"></span></div></div></div></div></div></div></div> <p></p> -- <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+unsubscribe@googlegroups.com" target="_blank">cp2k+unsubscribe@googlegroups.com</a>.<br> To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/CACTJSRcss5G9RC96xHDA9DO0idNTms%3D1giSnrT6-Nuizs5ybeA%40mail.gmail.com?utm_medium=email&utm_source=footer" target="_blank">https://groups.google.com/d/msgid/cp2k/CACTJSRcss5G9RC96xHDA9DO0idNTms%3D1giSnrT6-Nuizs5ybeA%40mail.gmail.com</a>.<br> </blockquote></div> <p></p> -- <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+unsubscribe@googlegroups.com">cp2k+unsubscribe@googlegroups.com</a>.<br /> To view this discussion on the web visit <a href="https://groups.google.com/d/msgid/cp2k/CAFg%3DAOjFR1QYFw18YpSru0oAuLRDL%3Du6PEAaP2WGPUW6opGD%3Dg%40mail.gmail.com?utm_medium=email&utm_source=footer">https://groups.google.com/d/msgid/cp2k/CAFg%3DAOjFR1QYFw18YpSru0oAuLRDL%3Du6PEAaP2WGPUW6opGD%3Dg%40mail.gmail.com</a>.<br />