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<p>If you look at the AFM Cr example of Exercise 7 on slide 17 of
[1], the struct file has Cr1 atom with a multiplicity of 1 at a
non-equivalent atomic position of (0,0,0) and it also has Cr2 atom
with a multiplicity of 1 at an non-equivalent atomic position of
(0.5, 0.5, 0.5). Since multiplicity is 1, there are no equivalent
atomic positions in this example.<br>
</p>
<p>At [2], you can see during the "instgen_lapw -ask" step during
execution of "init_lapw" that "u" was entered for Cr1 and "d" was
entered for Cr2. After the scf calculation, the Cr1 moment from
the calculation was 1.13184 for MMI001 and the Cr2 moment was
-1.13184 for MMI002. The Cr1 and Cr2 are antiferromagnetic [3]
with their moments having equal magnitude and opposite sign
resulting zero total moment (MMTOT).<br>
</p>
<p>Similar for your case, I think you need to ask and answer
yourself the same questions as you would for the above example.
In other words: What are the non-equivalent atomic positions for
Cr (but for Fe and Ni in your case)? What is the multiplicity of
each non-equivalent atomic position? What are the equivalent
atomic position for Cr (i.e, Fe and Ni in your case), if any?
What atoms at the non-equivalent and equivalent [4] atomic
positions give the AFM configuration(s) of interest and are
expected to cancel to give a zero total moment? Of note, if you
not familiar with what the multiplicity is in the struct file,
refer to section "4.3. THE CASE.STRUCT.FILE" on page 40 in the
usersguide for WIEN2k 19.1 and 19.2 [5].</p>
<p>I realize the use of runafm_lapw in the above Cr example might be
misleading as runsp_lapw typically has to be used in most cases as
explained in previous posts in the mailing list archive such as
[6-8].<br>
</p>
<p>Also, since the configuration set in case.inst with instgen_lapw
is just the initial one that could change during the scf as
explained in [9,10], don't forget to check the final magnetic
order that comes out of the scf to see if you have AFM or not
[11].<br>
</p>
<p>Though, in some cases when the scf does not result in the
expected spin state, it might be possible to force a particular
state as described in previous posts in the mailing list archive
such as [12-14].<br>
</p>
<p>There used to be a presentation online that I think illustrated
WIEN2k calculations on a structure for different AFM
configurations like Type G, Type A, and Type C that might been of
interest to you, but unfortunately I could not find it again in a
Google search. So something might have happened to the website
that was hosting it. It might have been the presentation "P.
Blaha: “Magnetic and charge order phase transition in YBaFe2O5"
seen in [15].<br>
</p>
[1] <a class="moz-txt-link-freetext" href="http://susi.theochem.tuwien.ac.at/events/ws2015/Exercises_15.pdf">http://susi.theochem.tuwien.ac.at/events/ws2015/Exercises_15.pdf</a><br>
[2]
<a class="moz-txt-link-freetext" href="http://wien2k-algerien1970.blogspot.com/2016/02/how-to-do-antiferromagnetic-calculation.html">http://wien2k-algerien1970.blogspot.com/2016/02/how-to-do-antiferromagnetic-calculation.html</a><br>
[3]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg13159.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg13159.html</a><br>
[4]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17879.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17879.html</a><br>
[5] <a class="moz-txt-link-freetext" href="http://www.wien2k.at/reg_user/textbooks/usersguide.pdf">http://www.wien2k.at/reg_user/textbooks/usersguide.pdf</a><br>
[6]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg16805.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg16805.html</a><br>
[7] <a class="moz-txt-link-freetext" href="http://susi.theochem.tuwien.ac.at/reg_user/faq/afm.html">http://susi.theochem.tuwien.ac.at/reg_user/faq/afm.html</a><br>
[8]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17307.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17307.html</a><br>
<div class="moz-cite-prefix">[9]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg03243.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg03243.html</a><br>
[10]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg06739.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg06739.html</a><br>
</div>
<div class="moz-cite-prefix">[11]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17516.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg17516.html</a></div>
<div class="moz-cite-prefix">[12]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18051.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18051.html</a><br>
</div>
<div class="moz-cite-prefix">[13]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18895.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg18895.html</a></div>
<div class="moz-cite-prefix">[14]
<a class="moz-txt-link-freetext" href="https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg19462.html">https://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/msg19462.html</a></div>
<div class="moz-cite-prefix">[15]
<a class="moz-txt-link-freetext" href="https://publik.tuwien.ac.at/files/PubDat_175934.pdf">https://publik.tuwien.ac.at/files/PubDat_175934.pdf</a><br>
</div>
<div class="moz-cite-prefix"><br>
</div>
<div class="moz-cite-prefix">On 10/13/2020 4:29 PM, BUSHRA SABIR
wrote:<br>
</div>
<blockquote type="cite"
cite="mid:1940413149.333839.1602628183616@mail.yahoo.com">
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<div class="ydp1ec1692byahoo-style-wrap"
style="font-family:Helvetica Neue, Helvetica, Arial,
sans-serif;font-size:16px;">
<div dir="ltr" data-setdir="false">Hi Wien2k users,</div>
<div dir="ltr" data-setdir="false"><br>
</div>
<div dir="ltr" data-setdir="false">I want to perform AFM
calculations for double perovskite oxide La2FeNiO6</div>
<div dir="ltr" data-setdir="false">For this, I have a cubic
225-Fm3m structure. </div>
<div dir="ltr" data-setdir="false">My question is ..Do I need to
flip the spin of Ni only during instgen_lapw -ask?</div>
<div dir="ltr" data-setdir="false">or should I make a supercell
with two Fe and then choose spin up for one Fe and spin dn for
second Fe.</div>
<div dir="ltr" data-setdir="false"><br>
</div>
<div dir="ltr" data-setdir="false">Need help for this</div>
<div dir="ltr" data-setdir="false"><br>
</div>
<div dir="ltr" data-setdir="false">Bushra</div>
</div>
</blockquote>
<blockquote type="cite"
cite="mid:1940413149.333839.1602628183616@mail.yahoo.com">
</blockquote>
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