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<div class="moz-cite-prefix">On 29/08/2024 12:36, Alex Kirkpatrick
wrote:<br>
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Thanks for the reply Lorenzo.</div>
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<br>
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I'm very new to all this but my thought was that, to have some
control over the distance between the 'electron' and the
surface, I would need to include it as a discrete entity. </div>
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<p>Hello, QE is a code based on plane waves, which means that you
cannot choose where an electron goes. But I don't think you need
to use an explicit electron for your task. Thank to the power of
numerical simulation, you can plot/measure directly the magnitude
of the Kohn-Sham potential, (which is identical to the Hartree
electrostatic potential when you go in the vacuum).</p>
<p>The procedure is similar to the one explained in the workfunction
example (PP/examples/WorkFct_example) which shows how to compute
the average value of the electrostatic potential far away in the
vacuum to estimate the energy required to pull an electron from
the surface out to infinity.</p>
<p>Of course the procedure is not entirely self-consistent (i.e.
pulling out the electron would change the potential) but for a
metal it is very close, and if you really need to you can remove
some amount of charge fro mthe surface using a positive value for
tot_charge</p>
<p>hth<br>
</p>
<p><br>
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<div class="elementToProof"
style="font-family: Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);">I
would then be able to vary the distance and see how things
change. Is this the wrong way to go about it?</div>
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Kind regards</div>
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Alex</div>
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<br>
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<div id="divRplyFwdMsg" dir="ltr"><span
style="font-family: Calibri, sans-serif; font-size: 11pt; color: rgb(0, 0, 0);"><b>From:</b> users
<a class="moz-txt-link-rfc2396E" href="mailto:users-bounces@lists.quantum-espresso.org"><users-bounces@lists.quantum-espresso.org></a> on behalf of
Lorenzo Paulatto <a class="moz-txt-link-rfc2396E" href="mailto:lorenzo.paulatto@cnrs.fr"><lorenzo.paulatto@cnrs.fr></a><br>
<b>Sent:</b> 29 August 2024 10:15<br>
<b>To:</b> Quantum ESPRESSO users Forum
<a class="moz-txt-link-rfc2396E" href="mailto:users@lists.quantum-espresso.org"><users@lists.quantum-espresso.org></a><br>
<b>Subject:</b> Re: [QE-users] Pseudopotential to approximate
a free electron?</span>
<div> </div>
</div>
<div style="direction: ltr;">You could, probably, but why not just
use tot_charge=-1<br>
<br>
Kind regards</div>
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<br>
</div>
<div style="direction: ltr;">On August 29, 2024 10:03:30 AM
GMT+02:00, Alex Kirkpatrick <a class="moz-txt-link-rfc2396E" href="mailto:canilivehere@hotmail.co.uk"><canilivehere@hotmail.co.uk></a>
wrote:</div>
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Dear all,</div>
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<br>
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Is it possible to create a pseudopotential file, or modify an
existing one like hydrogen, to approximate placing a free
electron in the simulation cell? </div>
<div
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The end goal being to model its interaction with material
surfaces in vacuum.</div>
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<br>
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Best wishes,</div>
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Alex</div>
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<br>
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<div class="moz-signature">-- <br>
<small>Dr. Lorenzo Paulatto<br>
IdR @ IMPMC - CNRS UMR 7590 & Sorbonne Université<br>
phone: +33 (0)1 442 79822 / skype: paulatz<br>
<a href="http://www.impmc.upmc.fr/~paulatto/"
class="moz-txt-link-freetext">http://www.impmc.upmc.fr/~paulatto/</a>
- <a href="https://anharmonic.github.io/"
class="moz-txt-link-freetext">https://anharmonic.github.io/</a><br>
23-24/423 B115, 4 place Jussieu 75252 Paris CX 05<small></small></small></div>
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