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<p>Dear Dorde,</p>
<p><br>
</p>
<p>The electronic configuration of Lu is [<a href="https://en.wikipedia.org/wiki/Xenon" title="Xenon">Xe</a>] 4f<sup>14</sup> 5d<sup>1</sup> 6s<sup>2
</sup><br>
</p>
<p><br>
</p>
<p>You are using QE v6.8 with the old Hubbard input syntax. The Hubbard manifold is hard-coded in this version and it is 4f for Lu (hubbard_l = 3). So you are trying to compute U for the 4f shell which is fully occupied.
<br>
</p>
<p><br>
</p>
<p>The HP code is based on linear-response theory (DFPT to 1st order) which can be used for open shells only. If you try to use it for closed shells (like you do), the U parameter will diverge in the self-consistent cycle. This is indeed what you observe. Please
have a look at this paper: <span>K. Yu and E.A. Carter, J. Chem. Phys. 140, 121105 (2014).</span></p>
<p><br>
</p>
<p>HTH</p>
<p><br>
</p>
<p><span style="font-family: Constantia, "Hoefler Text", serif;">Iurii</span><br>
</p>
<p><br>
</p>
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<div id="divRplyFwdMsg" dir="ltr"><font face="Calibri, sans-serif" style="font-size:11pt" color="#000000"><b>From:</b> users <users-bounces@lists.quantum-espresso.org> on behalf of Dorde DANGIC <dorde.dangic@ehu.eus><br>
<b>Sent:</b> Wednesday, October 11, 2023 9:57:58 AM<br>
<b>To:</b> users@lists.quantum-espresso.org<br>
<b>Subject:</b> [QE-users] Self-consistent calculation of Hubbard U parameter diverges</font>
<div> </div>
</div>
<div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
Dear all,</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<br>
</div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
I have tried to calculate the Hubbard U parameter self-consistently using hp.x code distributed with quantum-espresso software. In my calculations, the estimate of the U parameter constantly increases with each iteration. I started with a value of 0.0001 in
the 0<span class="ContentPasted0 ContentPasted1 ContentPasted2 ContentPasted5"><sup>th</sup> iteration, relaxed the structure, and ran scf calculation followed by hp.x calculation. The first estimate of the U parameter is 25.6456 eV. I ran the second iteration
with this value (relaxed the structure and ran scf.x/hp.x) and got the second estimate of 116.1282 eV. On the third iteration, U was 1073.3687 eV. I tried calculations with 'ortho-atomic' and 'atomic' projections. I tried calculations with the different starting
U. I always get the divergence of the U parameter. I am using v.6.8 version of quantum-espresso. I attached pw.in and hp.in. Am I doing something wrong? If not, what could be the reason for this behavior?</span></div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span class="ContentPasted0 ContentPasted1 ContentPasted2"><br>
</span></div>
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<span class="ContentPasted0 ContentPasted1 ContentPasted2">pw.in:</span></div>
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<span class="ContentPasted0 ContentPasted1 ContentPasted2"><br>
</span></div>
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<span class="ContentPasted0 ContentPasted1 ContentPasted2">
<div class="ContentPasted3">&control</div>
<div class="ContentPasted3"> prefix = 'LuH'</div>
<div class="ContentPasted3"> calculation = "scf"</div>
<div class="ContentPasted3"> tprnfor = .true.</div>
<div class="ContentPasted3"> tstress = .true.</div>
<div class="ContentPasted3"> outdir='./'</div>
<div class="ContentPasted3"> pseudo_dir='/scratch/djordjedangic/LuNH/'</div>
<div class="ContentPasted3">&end</div>
<div class="ContentPasted3">&system</div>
<div class="ContentPasted3"> ibrav = 0 </div>
<div class="ContentPasted3"> nat = 4</div>
<div class="ContentPasted3"> ntyp = 2</div>
<div class="ContentPasted3"> ecutwfc = 100.0</div>
<div class="ContentPasted3"> occupations = 'smearing'</div>
<div class="ContentPasted3"> smearing = 'gaussian'</div>
<div class="ContentPasted3"> degauss = 0.015</div>
<div class="ContentPasted3"> input_dft = 'pbe'</div>
<div class="ContentPasted3"> lda_plus_u = .true.</div>
<div class="ContentPasted3"> lda_plus_u_kind = 0</div>
<div class="ContentPasted3"> U_projection_type = 'ortho-atomic'</div>
<div class="ContentPasted3"> Hubbard_U(1) = 0.0001</div>
<div class="ContentPasted3">&end</div>
<div class="ContentPasted3">&electrons</div>
<div class="ContentPasted3"> conv_thr = 1e-14</div>
<div class="ContentPasted3">&end</div>
<div><br class="ContentPasted3">
</div>
<div class="ContentPasted3">ATOMIC_SPECIES</div>
<div class="ContentPasted3">Lu 174.9668 Lu.upf</div>
<div class="ContentPasted3">H 1.00784 H.upf</div>
<div><br class="ContentPasted3">
</div>
<div class="ContentPasted3">K_POINTS automatic</div>
<div class="ContentPasted3">12 12 12 0 0 0</div>
<div><br class="ContentPasted3">
</div>
<div class="ContentPasted3">CELL_PARAMETERS (angstrom)</div>
<div class="ContentPasted3"> -2.494212191 -0.000000000 2.494212191</div>
<div class="ContentPasted3"> 0.000000000 2.494212191 2.494212191</div>
<div class="ContentPasted3"> -2.494212191 2.494212191 -0.000000000</div>
<div><br class="ContentPasted3">
</div>
<div class="ContentPasted3">ATOMIC_POSITIONS (crystal)</div>
<div class="ContentPasted3">Lu -0.0000000000 0.0000000000 -0.0000000000</div>
<div class="ContentPasted3">H 0.2500000000 0.2500000000 0.2500000000</div>
<div class="ContentPasted3">H 0.7500000000 0.7500000000 0.7500000000</div>
<div class="ContentPasted3">H 0.5000000000 0.5000000000 0.5000000000</div>
<br>
</span></div>
<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span class="ContentPasted0 ContentPasted1 ContentPasted2">hp.in:</span></div>
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<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span class="ContentPasted0 ContentPasted1 ContentPasted2 ContentPasted4">&inputhp
<div class="ContentPasted4"> prefix = 'LuH'</div>
<div class="ContentPasted4"> outdir='./'</div>
<div class="ContentPasted4"> nq1=6</div>
<div class="ContentPasted4"> nq2=6</div>
<div class="ContentPasted4"> nq3=6</div>
<div class="ContentPasted4"> conv_thr_chi=1.0d-12 </div>
<div class="ContentPasted4">/</div>
<br>
</span></div>
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<span class="ContentPasted0 ContentPasted1 ContentPasted2 ContentPasted4">Kind regards,</span></div>
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<span class="ContentPasted0 ContentPasted1 ContentPasted2 ContentPasted4"><br>
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<div style="font-family: Aptos, Aptos_EmbeddedFont, Aptos_MSFontService, Calibri, Helvetica, sans-serif; font-size: 12pt; color: rgb(0, 0, 0);" class="elementToProof">
<span class="ContentPasted0 ContentPasted1 ContentPasted2 ContentPasted4">Dorde<br>
</span></div>
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