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<p>Dear Corina,</p>
<p><br>
</p>
<p>Please do not forget to indicate your affiliation.</p>
<p><br>
</p>
<p>You are trying to model a V-O dimer, right? Note that DFT+U+V was designed for periodic solids. Also note that a
<b>virtual </b>3x3x3 supercell is created in DFT+U+V to find the indices of neighboring atoms to assign the inter-site Hubbard V interaction (please see the discussion on page 11 in this paper:
<span class="arxivid"><a href="https://arxiv.org/abs/2203.15684">arXiv:2203.15684</a></span>). </p>
<p><br>
</p>
<p>In order to solve your problem just change the value of the parameter "eps" to e.g.
<span>5.d-5</span> in PW/src/<span>intersite_V.f90</span> and then recompile the code. Note that the default value "<span>eps = 5.d-6</span>" works in the majority of cases (at least for periodic solids).
<br>
</p>
<p><br>
</p>
<p>HTH</p>
<p><br>
</p>
<p>Greetings,</p>
<p>Iurii<br>
</p>
<p><br>
</p>
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<font size="3" face="'Times New Roman', Times, serif" color="808080">--<br>
<span style="font-family:Cambria,Georgia,serif">Dr. Iurii TIMROV</span><br>
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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 Corina Urdaniz <urdaniz.corina@qns.science><br>
<b>Sent:</b> Wednesday, June 8, 2022 5:24:24 AM<br>
<b>To:</b> users@lists.quantum-espresso.org<br>
<b>Subject:</b> [QE-users] problems with DFT+U+V (No atom equivalent to r2 error)</font>
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<div>Dear All, i'm new in QE, i running DFT+U+V in simple system (see input below), and i obtain this error message:
<br>
</div>
<div><br>
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<div>I diff > 0, diff= 1.00000000000000 at1= 1 at2= 1<br>
<br>
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br>
Error in routine symonpair (1):<br>
No atom equivalent to r2</div>
<div>%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%</div>
<div><br>
</div>
<div> I'm running too in the new development version and I obtain the same error.</div>
<br>
<div>&control<br>
calculation = "scf"<br>
prefix = "xxx"<br>
pseudo_dir = "xxxxxx"<br>
outdir = "./tmp"<br>
restart_mode = "from_scratch"<br>
nstep = 500<br>
/<br>
&system<br>
ibrav=6,<br>
A=12.375<br>
C= 29<br>
nat=2,<br>
ntyp=2,<br>
ecutwfc =70,<br>
ecutrho= 600,<br>
occupations='smearing',<br>
smearing='mv'<br>
degauss=0.005<br>
starting_magnetization(1)=0.7<br>
starting_magnetization(2)=-0.07<br>
vdw_corr = 'grimme-d3'<br>
nspin=2<br>
lda_plus_u = .true.<br>
lda_plus_u_kind = 2<br>
U_projection_type = 'ortho-atomic',<br>
Hubbard_V(1,1,1)=1<br>
Hubbard_V(1,2,2)=2<br>
/<br>
&electrons<br>
electron_maxstep = 500,<br>
conv_thr = 1.0D-8,<br>
mixing_beta = 0.3,<br>
/<br>
&IONS<br>
/<br>
ATOMIC_SPECIES<br>
V 50.9415 v_pbe_v1.4.uspp.F.UPF<br>
O 15.999 O.pbe-n-kjpaw_psl.0.1.UPF<br>
ATOMIC_POSITIONS (angstrom)<br>
V 5.1550456485 5.1550098098 14.1845777826<br>
O 5.1549976674 5.1549967180 12.0833856727<br>
K_POINTS automatic<br>
1 1 1 0 0 0<br>
</div>
<div><br>
</div>
<div><b>for the new development i try with this card:</b></div>
<div>HUBBARD (ortho-atomic)<br>
V V-3d V-3d 1 1 1.2<br>
V V-3d V-4s 1 1 0.5<br>
V V-3d O-2p 1 2 2<br>
V V-4s V-4s 1 1 0.5<br>
</div>
<div><br>
</div>
<div><br>
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<div><b>the problem was solved when i changed the coordinates to something like:</b>
<br>
</div>
<div><br>
</div>
<div>ATOMIC_POSITIONS (angstrom)<br>
</div>
<div>V 0.0 0.0 0.0<br>
</div>
<div>O 0.0 0.0 2.0<br>
</div>
<div><br>
</div>
<div>
<pre class="gmail-tw-data-text gmail-tw-text-large gmail-tw-ta" id="gmail-tw-target-text" style="text-align:left" dir="ltr"><span class="gmail-Y2IQFc" lang="en"><br></span></pre>
</div>
<div>but I get the same error as above if I use the positions from relax.out<br>
</div>
<div><br>
</div>
<div>
<div>
<div>Is it a bug, or is it just the question of some parameter tweaking?</div>
<div><br>
</div>
<div><br>
</div>
<div>TIA!</div>
<div><br>
</div>
<div>all the best,</div>
<div><br>
</div>
<div>Corina.</div>
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