<div dir="ltr">Dear Nicola,<div><br></div><div>Thank you very much for your quick response and for sharing the wiki article to learn more about the oscdft method. This is very useful.</div><div><br></div><div>Best regards,</div><div><br></div><div>Alain.</div></div><br><div class="gmail_quote gmail_quote_container"><div dir="ltr" class="gmail_attr">On Wed, Feb 18, 2026 at 3:20 AM Nicola Marzari <<a href="mailto:nicola.marzari@epfl.ch">nicola.marzari@epfl.ch</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">



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Dear Alain,
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<div>a summary is here:</div>
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but nothing is available out of the box.</div>
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<div>Probably easiest (but come coding) would be a U on a projector that is an appropriate linear combination of atomic projectors that approximate the homo or lumo of the adsorbate (poor-man-Wannier).  We did some molecular U with Ismaila Dabo a long time
 ago: <a href="https://pubs.acs.org/doi/10.1021/ja067944u" target="_blank">https://pubs.acs.org/doi/10.1021/ja067944u</a></div>
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<div>Then you adapt os-cdft.</div>
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<div>Other options would be U on the actual eigenstate or Wannier function - this latter I believe is work in progress.</div>
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<div>Nicola</div>
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<div>Sent from a tiny keyboard... Contact info:</div>
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<div><a href="http://theos-wiki.epfl.ch/Main/Contact" target="_blank">http://theos-wiki.epfl.ch/Main/Contact</a></div>
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<blockquote type="cite">On 17 Feb 2026, at 19:06, Alain Delgado Gran via users <<a href="mailto:users@lists.quantum-espresso.org" target="_blank">users@lists.quantum-espresso.org</a>> wrote:<br>
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<div dir="ltr">Hello QE users/developers,
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<div>Context:</div>
<div>I want to build diabatic potential energy surfaces for a molecule close to a metal surface for different charges (+1, 0) of the adsorbate.</div>
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<div>Question:</div>
<div><span id="m_-9129274172073582243gmail-docs-internal-guid-ee23ce55-7fff-dbbe-15e9-136e126ebffd"><span style="font-family:Inter,sans-serif;color:rgb(31,31,31);font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;vertical-align:baseline">Is
 constrained DFT (cDFT) implemented in QE in a way that allows it to be used for constructing diabatic states? I am aware of the</span><a href="https://www.quantum-espresso.org/Doc/INPUT_OSCDFT.html" style="text-decoration-line:none" target="_blank"><span style="font-family:Inter,sans-serif;color:rgb(31,31,31);font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;vertical-align:baseline">
</span><span style="font-family:Arial,sans-serif;background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;text-decoration-line:underline;vertical-align:baseline">OS-CDFT module</span></a><span style="font-family:Arial,sans-serif;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;vertical-align:baseline">,
 which controls the oxidation state of a transition-metal element, but it appears not to be generalizable for constraining charge within an arbitrary molecular region. Is this interpretation correct? If not, where can I find a good example or tutorial on how
 to perform this type of calculation?</span></span></div>
<div><span><span style="font-family:Arial,sans-serif;color:rgb(0,0,0);background-color:transparent;font-variant-numeric:normal;font-variant-east-asian:normal;font-variant-alternates:normal;vertical-align:baseline"><br>
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<div><font color="#000000" face="Arial, sans-serif"><span>Thank you for your time and attention.</span></font></div>
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<div><font color="#000000" face="Arial, sans-serif"><span>Best regards,</span></font></div>
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<div><font color="#000000" face="Arial, sans-serif"><span>Alain.</span></font></div>
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