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<p>Hi,</p>
<p>Sodium metal has an odd number of electrons per primitive unit
cell (which contains a single atom), and however is nonmagnetic.
The same applies to aluminum. This is the result of having a large
overlap between orbitals, making the (in principle) spin up and
spin down energy separation much smaller than the bandwidth so
that spin up and down electrons are equaled in population. Did you
verify whether this is your case?</p>
<p>Regards,</p>
<p>José Carlos<br>
</p>
<div class="moz-cite-prefix">El 16/07/2019 a las 15:34, Ayestaran
Latorre, Carlos escribió:<br>
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Hi,</div>
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<br>
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I have a system consistent of a diamond slab with a boron
substitutional defect, an adsorbed hydroxyl and an adsorbed
hydrogen on the surface. The system has an odd number of
electrons (487) and I run a spin polarized (nspin=2) structural
relaxation (see attached). One would expect an odd value for the
total magnetization, but the it quickly converges to zero.
<br>
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I assumed this would be a side effect of smearing allowing
partial electronic occupations (I employed gaussian smearing
with degauss=0.02). I tried lowering the smearing value down to
0.001, both for gaussian and mv smearing, but only managed to
get total magnetization ~ 0.3 Bohr mag/cell in both cases.
Fixing tot_magnetization=1, however, yields a noticeably higher
final energy (~0.3 eV).</div>
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When I run a structural relaxation on a similar system (with an
adsorbed H2O molecule instead of the hydroxyl+hydrogen
fragments), the total magnetization satisfyingly reaches 1 Bohr
mag/cell rather quickly. Other combinations (for example,
without the H2O molecule at all) also give total magnetization
values that don't match the even/odd number of electrons.</div>
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<br>
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Regards,</div>
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Carlos Ayestaran Latorre</div>
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<br>
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