<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
</head>
<body text="#000000" bgcolor="#FFFFFF">
<p>Sorry, I don't know, but maybe more details about your
calculation would be needed for someone else to answer your
question.</p>
<p>For example, are you doing something similar to the Constraint U
exercise [
<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>
], which uses the F^0_eff formula of EPL vol. 69, 777 (2005) [
<a class="moz-txt-link-freetext" href="https://doi.org/10.1209/epl/i2004-10416-x">https://doi.org/10.1209/epl/i2004-10416-x</a> ,
<a class="moz-txt-link-freetext" href="https://arxiv.org/abs/cond-mat/0412560v1">https://arxiv.org/abs/cond-mat/0412560v1</a> (equation 4)]?</p>
<p>For NiO [
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14460.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg14460.html</a>
,
<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>
], I think that gave about:<br>
</p>
<p>ε3d_up = 0.119</p>
<p>ε3d_dn = -0.282</p>
<p>If those are the same parameters as in equation 11 of Phys. Rev.
B vol. 44, 943 (1991) [ <span class="doi-field"><a class="moz-txt-link-freetext" href="https://doi.org/10.1103/PhysRevB.44.943">https://doi.org/10.1103/PhysRevB.44.943</a></span>
], then it looks like that would be:</p>
<p>J = ε3d_up - ε3d_dn = 0.12 - (-0.28) = 0.401<br>
</p>
<p>Though, one has to keep in mind that the Ueff values obtained
from the Constrained method are known to be of questionable
accuracy [
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15599.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg15599.html</a>
]. So, the J values might be of questionable accuracy as well.
In addition, well converge results can be needed for such
calculations [
<a class="moz-txt-link-freetext" href="https://www.researchgate.net/post/How_to_calculate_U_and_or_J_values_of_DFT_U">https://www.researchgate.net/post/How_to_calculate_U_and_or_J_values_of_DFT_U</a>
].<br>
</p>
<div class="moz-cite-prefix">On 5/12/2018 6:28 AM, Wien2k User
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:CAHYowjFxpbSwK6VQdmRQhEBYHUf+v+XMaUmHrpVJFeofQZuq5w@mail.gmail.com">
<div dir="ltr">
<div>
<font size="4" face="times new roman, serif"><span
style="color:rgb(34,34,34);font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">Dear
Prof. Tran and WIEN2k users;</span>
<br>
</font></div>
<div><font size="4" face="times new roman, serif"><br>
</font></div>
<div><font size="4" face="times new roman, serif">I found in <span
style="color:rgb(85,85,85)">Anisimov's paper the following
relation to calculate J</span></font></div>
<div><span style="color:rgb(85,85,85)"><font size="4"
face="times new roman, serif">
<span
style="color:rgb(34,34,34);font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">J=E3d'up'(n+0.5,n-0.5)-<span> </span></span><span
style="color:rgb(34,34,34);font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial;background-color:rgb(255,255,255);float:none;display:inline">E3d'dn'(n+0.5,n-0.5)</span> </font></span></div>
<div><font size="4" face="times new roman, serif">but I think
that the energy of the spin-up electrons is more stable
compared to that of Dn electrons and that's why I found a
negative energy (Do you think that this relationship is
reversed?) or my reasoning is wrong and I have to review my
calculations?</font></div>
<div><font size="4" face="times new roman, serif"><br>
</font></div>
<div><font size="4" face="times new roman, serif">Thank you in
advance </font></div>
</div>
<div class="gmail_extra"><br>
<div class="gmail_quote">2018-05-11 18:47 GMT+02:00 Wien2k User
<span dir="ltr"><<a href="mailto:wien2k.user@gmail.com"
target="_blank" moz-do-not-send="true">wien2k.user@gmail.com</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">Thank you very much</div>
<div class="HOEnZb">
<div class="h5">
<div class="gmail_extra"><br>
<div class="gmail_quote">2018-05-11 16:09 GMT+02:00
Wien2k User <span dir="ltr"><<a
href="mailto:wien2k.user@gmail.com"
target="_blank" moz-do-not-send="true">wien2k.user@gmail.com</a>></span>:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">Dear Prof. P. BLAHA and WIEN2k
users;
<div><br>
</div>
<div>I want to estimate the effective value of
Hubbard term "Ueff=U-J"</div>
<div><br>
</div>
<div>Can the Hund's Exchange parameter (J) be
negative? </div>
<div><br>
</div>
<div>Thank you very much.</div>
</div>
</blockquote>
</div>
<br>
</div>
</div>
</div>
</blockquote>
</div>
</div>
</blockquote>
</body>
</html>