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<div class="moz-cite-prefix">Dear Bo and Lorenzo,<br>
<br>
I have one more suggestion on the issue of phonon branch sorting.
I ran into this problem a while back, while working on a project
on thermal transport in indium arsenide nanowires. I ended up
using an sorting algorithm that Keith Refson developed for use
with phonon calculations in the CASTEP code. This script works by
calculating overlap matrices between eigenvectors at neighboring
q-points. Keith recently licensed this script as GPL and I have
written a tool to convert the matdyn phonon output to the CASTEP
phonon format. For my project, I found that as long as you have a
fairly dense mesh of q-points, it worked very well.<br>
<br>
I am planning to put these scripts up on the web soon once I have
a short example run to go with it. I'll send a note to the PWSCF
forum when it is ready. Bo, in the meantime, I would be happy to
send you the scripts if you are interested.<br>
<br>
Best regards,<br>
<br>
Derek<br>
<br>
<pre class="moz-signature" cols="72">################################
Derek Stewart, Ph. D.
Senior Research Associate
<a class="moz-txt-link-freetext" href="http://sites.google.com/site/dft4nano/">http://sites.google.com/site/dft4nano/</a>
250 Duffield Hall
Cornell Nanoscale Facility (CNF)
Ithaca, NY 14853
stewart (at) cnf.cornell.edu
(607) 255-2856
</pre>
On 10/26/2012 8:00 AM, Lorenzo Paulatto wrote:<br>
</div>
<blockquote
cite="mid:CAG+GtJcWu-UxWHQFasfrmU1NKvKb4fFRN-y+G+n8s49it5pkKw@mail.gmail.com"
type="cite">On 26 October 2012 07:55, Bo Qiu <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:200210qb@gmail.com"
target="_blank">200210qb@gmail.com</a>></span> wrote:<br>
<div class="gmail_quote">
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
Dear Dr. Paulatto,
<div><br>
</div>
<div>Thanks a lot for the explanations! I'm actually writing a
small code to order phonon bands based on eigenvector
continuities on a 3d grid. Thanks for pointing out there
is already such option in matdyn.x, I'll definitely check it
out. I have finished a preliminary test for my code on Al
for a band crossing along Gamma-K direction -- it seems to
be well captured, but band orderings are wrong at some
random point where there is actually no band crossing. I'll
try to figure it out and also referring to the matdyn.f90 to
see what else I can do. </div>
<div>On the other hand, I think for electronic band structures
one will have the same problem with band ordering -- though
most of time people are only interested about those very few
bands near Fermi level. I wonder in the case of electronic
band structure whether continuity of wavefunction should be
used to deal with band ordering with band crossing? Thanks a
lot!</div>
<span class="HOEnZb"><font color="#888888">
<div><br>
</div>
</font></span>
<div><span class="HOEnZb"></span></div>
</blockquote>
</div>
<div><br>
</div>
<div>The bands.x code already does that, i.e. it sorts the bands
using the overlap of wavefunctions at consequent k-points.
Again, this is an option that works well for line plots, but I'm
not sure it always make sense to use in a 3D dispersion. Or at
least, it would need to be modified to sort according
to neighboring points, not just according to the previous point
in the input list. It is not very hard to do, but a bit boring
as it requires a rethinking of the code structures.</div>
<div><br>
</div>
<div>bests</div>
<div><br>
</div>
-- <br>
<div>Dr. Lorenzo Paulatto </div>
<div>IdR @ IMPMC -- CNRS & Université Paris 6</div>
<div>phone: +33 (0)1 44275 084 / skype: paulatz</div>
<div>www: <a moz-do-not-send="true"
href="http://www-int.impmc.upmc.fr/%7Epaulatto/"
target="_blank">http://www-int.impmc.upmc.fr/~paulatto/</a></div>
<div>mail: 23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252
Paris Cédex 05</div>
<br>
<div><br>
</div>
<div><br>
</div>
<br>
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</blockquote>
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