<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><div class="">Dear Quantum Espresso friends,</div><div class=""><br class=""></div><div class="">I have relaxed a Pt(111) surface with 5 metal layers and S_2 symmetry :)</div><div class=""><br class=""></div><div class="">To validate the calculations, I like to plot the x,y-averaged electrostatic potential</div><div class="">along the z-coordinate of the unit cell.</div><div class=""><br class=""></div><div class="">I have used pp.x and the following input file (pt.ppi) to obtain the values for the electrostatic </div><div class="">potential on a grid. Please correct me if I’m wrong, but I thought it was the FFT grid.</div><div class=""><br class=""></div><div class="">pt.ppi:</div><div class=""><snip></div><div class=""><div class="">$inputPP</div><div class=""> outdir='.'</div><div class=""> plot_num=11</div><div class=""> filplot = 'Pt111_5M3V2x2.estatic.pot'</div><div class="">/</div></div><div class=""></snip></div><div class=""><br class=""></div><div class="">As expected `pp.x < pt.ppi` yielded Pt111_5M3V2x2.estatic.pot.</div><div class=""><br class=""></div><div class="">I then used average.x and the following input file (pt.avi) to obtain the x,y-averaged values</div><div class="">for the electrostatic potential along the z-coordinate of the unit cell. </div><div class=""><br class=""></div><div class="">pt.avi</div><div class=""><snip></div><div class="">1</div><div class="">Pt111_5M3V2x2.estatic.pot</div><div class="">1.0</div><div class="">1440</div><div class="">3</div><div class="">3.835000000</div><div class=""></snip></div><div class=""><br class=""></div><div class="">`average.x < pt.avi` yielded a avg.dat file.</div><div class=""><br class=""></div><div class="">I then plotted the the first and second column of avg.dat file with gnuplot. The plot is attached to this e-mail.</div><div class=""><br class=""></div><div class="">According to <a href="https://www.quantum-espresso.org/Doc/INPUT_PP.html#idm24:" class="">https://www.quantum-espresso.org/Doc/INPUT_PP.html#idm24:</a> "</div><span class=""><br class=""></span><span class="">All potentials have the dimension of an energy (e*V, not V).</span>”<div class=""><span class=""><br class=""></span></div><div class=""><span class="">So, the graph shows that the electrostatic potential varies between ca. -0.4 eV and ca. 1 eV.</span></div><div class="">So the vacuum electrostatic potential is about 1 eV.</div><div class=""><span class=""><br class=""></span></div><div class=""><span class="">According to the pw.x calculation, the Fermi energy is </span>8.2481 eV<span class=""><br class=""><br class="">This is not consistent to my idea. I would have expected a Fermi energy smaller than 1 eV, or a</span></div><div class="">vacuum electrostatic potential > 8.2481 eV.</div><div class=""><span class=""><br class=""></span></div><div class=""><span class="">What am I doing wrong? Did I plot the electrostatic potential?<br class=""><br class=""></span><span class=""><br class=""></span><span class=""><img apple-inline="yes" id="75A9AF68-7BAE-4BE5-B981-4427A9F0C273" src="cid:5707B4B3-D7FC-4F29-BACA-362BCF833E99" class=""></span><span class=""><br class=""><br class=""></span><span class=""><br class=""></span><span class=""><br class=""></span><span class=""><div class="">Met vriendelijke groeten,<br class="">Mit freundlichen Grüßen,<br class="">With kind regards,<br class=""><br class=""><br class="">Willem Offermans<br class="">Researcher Electrocatalysis SCT<br class="">VITO NV | Boeretang 200 | 2400 Mol<br class="">Phone:+32(0)14335263 Mobile:+32(0)492182073 <br class=""><br class=""><a href="mailto:Willem.Offermans@Vito.be" class="">Willem.Offermans@Vito.be</a><br class=""><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none;"><br class="Apple-interchange-newline" style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;"><span style="caret-color: rgb(0, 0, 0); color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; text-decoration: none;"><span><img apple-inline="yes" id="2A47E5B5-AAC7-4C8C-B1DE-DF56368CE7A5" src="cid:982BA063-B96A-4A1B-89AB-5A01CA9FC70D@vito.local" class=""></span>
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