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On 09/28/2014 11:23 PM, Alaska Subedi wrote:<br>
<blockquote
cite="mid:CAJdU21OUJGCWdytv4nBYsFrV-=QZOBGLnaTNWWC8NbcBi7MRSQ@mail.gmail.com"
type="cite">
<pre wrap=""> So it would be
nice to do the symmetry analysis of the phonons by ignoring the
antiferromagnetic order.
</pre>
</blockquote>
<br>
Dear Alaska,<br>
<br>
there is something you could try, I do not know if it is enough for
your needs.<br>
<br>
First of all you need to do a normal phonon calculation, with the
antiferro symmetry. Then you take the dynamical matrix files and
you edit them by hand, setting the two inequivalent Mn species to
the same. E.g. let's say your header is like this:<br>
<br>
Dynamical matrix file<br>
<br>
2 2 2 7.7249000 0.0000000 0.0000000 0.0000000 0.0000000
0.0000000<br>
1 'Mn1 ' 96995.8962477164 <br>
2 'Mn2' 96995.8962477164 <br>
1 1 0.0000000 0.0000000 0.0000000<br>
2 2 -0.5000000 0.5000000 0.5000000<br>
<br>
You change it to:<br>
<br>
2 2 2 7.7249000 0.0000000 0.0000000 0.0000000 0.0000000
0.0000000<br>
1 'Mn1 ' 96995.8962477164 <br>
2 'Mn2' 96995.8962477164 <br>
1 1 0.0000000 0.0000000 0.0000000<br>
2 <b><font color="#ff0000">1</font></b> -0.5000000
0.5000000 0.5000000<br>
<br>
I.e. you set <i>all</i> the atoms of type Mn2 to be of type Mn1. No
need to completely remove the Mn2 specie, it only make things more
complicated.<br>
<br>
Then you resymmetrize the file with the q2qstar.x program from the
phonon suite:<br>
q2qstar.x input.dyn output.dyn<br>
The new file will have the symmetry of the non-magnetic system. <br>
<br>
I do not guarantee that it makes sense, but it may be enough for
your application.<br>
<br>
kind regards<br>
<br>
<pre class="moz-signature" cols="72">--
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Université Paris 6
+33 (0)1 44 275 084 / skype: paulatz
<a class="moz-txt-link-freetext" href="http://www-int.impmc.upmc.fr/~paulatto/">http://www-int.impmc.upmc.fr/~paulatto/</a>
23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05 </pre>
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