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<div class="moz-cite-prefix">The NiO example [1] with 1 k-point gave
about 6 eV with the NiO_+.5-1 calculation taking about 36 cycles
[2,3]. N.B. [4], this is with 2.00 and not 20.3 in case.in1. I
believe the 20.3 in the paper may be a typographical error. At the
bottom of [1], there is the statement:<br>
<br>
Usually, it is better to just set the d energy 2-4 Ry above the
Fermi level.<br>
<br>
The Fermi level is not known when starting the calculation, but a
small value of about 0 is likely a reasonable assumption. So let
Fermi level = 0. Taking the lower value of 2 Ry from the
statement above. So took 2.00 for case.in1. I think the Fermi
level obtained after the calculation was about 0.5. If you round
that down, it becomes zero. So it seems the 0 was likely an okay
starting assumption.<br>
<br>
I suspect 1 k-point and 5 RKmax wouldn't be used if it was a
proper calculation, but the paper is an example such that it was
likely chosen for speed [5].<br>
<br>
For example, it looks like 100 k-points and 5.7 RKmax (instead of
1 k-point and 5 RKmax) were used in G. K. H. Madsen and P. Novak
calculation for Fe3O4 [6].<br>
<br>
Keep in mind that the Ueff values obtained from the Constrained
method are known to be of questionable accuracy [7].<br>
<br>
Rather than your two choices below, it is better to do convergence
tests [8-12].<br>
<br>
[1]
<a class="moz-txt-link-freetext" href="http://susi.theochem.tuwien.ac.at/reg_user/textbooks/Constraint_U.pdf">http://susi.theochem.tuwien.ac.at/reg_user/textbooks/Constraint_U.pdf</a><br>
[2]
<a class="moz-txt-link-freetext" href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14460.html">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14460.html</a><br>
[3]
<a class="moz-txt-link-freetext" href="http://wien2k-algerien1970.blogspot.com/2016/08/how-to-calculate-u-parameter-in-nickel.html">http://wien2k-algerien1970.blogspot.com/2016/08/how-to-calculate-u-parameter-in-nickel.html</a><br>
[4] <a class="moz-txt-link-freetext" href="https://en.wikipedia.org/wiki/Nota_bene">https://en.wikipedia.org/wiki/Nota_bene</a><br>
[5]
<a class="moz-txt-link-freetext" href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15593.html">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15593.html</a><br>
[6] <a class="moz-txt-link-freetext" href="https://arxiv.org/abs/cond-mat/0412560v1">https://arxiv.org/abs/cond-mat/0412560v1</a><br>
[7]
<a class="moz-txt-link-freetext" href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg12429.html">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg12429.html</a><br>
[8]
<a class="moz-txt-link-freetext" href="http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15596.html">http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15596.html</a><br>
[9]
<a class="moz-txt-link-freetext" href="http://wien2k-algerien1970.blogspot.com/2016/08/kpoint-convergence-test.html">http://wien2k-algerien1970.blogspot.com/2016/08/kpoint-convergence-test.html</a><br>
[10]
<a class="moz-txt-link-freetext" href="https://www.beilstein-journals.org/bjnano/content/supplementary/2190-4286-2-45-S1.pdf">https://www.beilstein-journals.org/bjnano/content/supplementary/2190-4286-2-45-S1.pdf</a><br>
[11]
<a class="moz-txt-link-freetext" href="http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg01700.html">http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg01700.html</a><br>
[12]
<a class="moz-txt-link-freetext" href="http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg08186.html">http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg08186.html</a>
<br>
<br>
On 3/27/2017 9:50 AM, karima Physique wrote:<br>
</div>
<blockquote
cite="mid:CAB25O4nk9oPs7xpqs3_gsebDbXih-hX1NU+6LgfDdZCxMB=nxA@mail.gmail.com"
type="cite">
<div dir="ltr">Thank you for your answer but i I noticed that Ueff
is very sensitive with the change of RKmax and Kpoint it is for
this I evoked this subject abd for example
<div>For K = 1 and RKmax 5 i found Ueff = 3.6 eV</div>
<div>But For K = 100 Points and RKmax 8.5 i found Ueff = 5.4 eV</div>
<div><br>
</div>
<div>5.4 and 3.6 are relatively far </div>
<div><br>
</div>
<div>What I really ask is that the choice of one point is it
mandatory? (as is indicated in the paper of <span
style="color:rgb(80,0,80);font-size:12.8px">G. K. H. Madsen
and P. Novak</span>) or else I have to force these
parameters (a large number of Kpoint and rkmax> 7) which of
these two choices is good</div>
</div>
</blockquote>
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