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<p>Dear QE experts,</p>
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<p> I recently perfomed a scf PBEsol calculation for Tb2Ti2O7 (attached the input file).
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<p> I would like to plot the difference between the scf charge density and the superposition</p>
<p> of atomic charge. For this purpose I used the PostProcessing tool (plut_num = 9).
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<p> I expected the integral of this difference to be ~0 , but I found it to be 4. After a quick check
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<p> I realized that the Ti pseudopotetial (GBRV-1.4, <span>ti_pbesol_v1.4.uspp.F.UPF</span>) was generated
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<p> in an ionized configuration with just 1 electron (instead of 2 ) in the 3d orbital. Since there
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<p> are 4 Ti in the primitive cell, I think this is the reason for the odd result described above.
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<p> Indeed during the initialization of a scf calculation for an isolated Ti atom I got:
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<div><span style="font-family: Consolas, Courier, monospace, serif, "EmojiFont";">Initial potential from superposition of free atoms</span><br>
<span style="font-family: Consolas, Courier, monospace, serif, "EmojiFont";"> Check: negative starting charge= -0.001319</span><br>
<span style="font-family: Consolas, Courier, monospace, serif, "EmojiFont";"> starting charge 10.99996, renormalised to 12.00000</span><br>
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<p> However this renormalization is not done in the PP, and in any case I do not think it would make sense there.
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<p> That said, my feeling is that I cannot completely trust the charge density difference.<br>
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<p> Do you have any advise on how to solve this problem (beside changing pseudo)?
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<p> Thank you in advance and best regards,</p>
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<p>Nicola Colonna <br>
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<font face="Helvetica"><span dir="ltr" id="divtagdefaultwrapper" style="font-size:12pt"><span style="font-size:13px"><span style="font-size:13px"><span style="font-size:13px">Nicola S. Colonna</span></span></span></span><br>
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<div style="text-indent:0"><font face="Helvetica">WHGA/150<br>
CH-5232 Villigen-PSI</font></div>
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