Dear QE-users and Paolo, <br><br>Thanks for your explanation. <br>Actually we can completely understand npert(irr). <br>However, there is still difficulty for us to relate npert(irr) to a specific \nu. <br><br>When we track the quantity "npert", we could not find out where it is modified (although we know it is defined in phcom.f90). <br>
<br>Would you please point out the relationship between npert and \nu? <br>Just point out which files we need to look into will be helpful.<br><br>Thanks,<br>Hua<br><br><br><div class="gmail_quote">On Mon, Dec 12, 2011 at 5:44 AM, Paolo Giannozzi <span dir="ltr"><<a href="mailto:giannozz@democritos.it">giannozz@democritos.it</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div class="im">On Sun, 2011-12-11 at 00:31 -0500, Ajit Vallabhaneni wrote:<br>
<br>
> I had gone thru the source code "elphon.f90" for this purpose.<br>
<br>
</div>wow! you are a brave man<br>
<div class="im"><br>
> I could figure out all the variables like k,i,j,q but not nu.<br>
> I see a variable 'imode0' which i cannot figure out its purpose.<br>
> Can someone please help me with identifying the nu ?<br>
<br>
</div>the el-ph matrix elements are calculated for each irrep, i.e.<br>
displacement patterns transforming into each other under the<br>
symmetry operations of the small group of each wavevector.<br>
There are nirr irreps, each having dimension npert(irr).<br>
The code runs over irreps: irr=1,..,nirr, then over irrep<br>
components: ipert=1,..,npert(irr), and imode0+ipert is the<br>
index of each displacement pattern. Only when the el-phon<br>
coefficient "gamma" is calculated are phonon modes (contained<br>
in matrix "dyn") actually used.<br>
<span class="HOEnZb"><font color="#888888"><br>
P.<br>
--<br>
Paolo Giannozzi, IOM-Democritos and University of Udine, Italy<br>
</font></span><div class="HOEnZb"><div class="h5"><br>
<br>
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