<div dir="ltr">It is really a tough but interesting work.<br><div class="gmail_extra"><br><br><div class="gmail_quote">2013/10/23 Laurence Marks <span dir="ltr"><<a href="mailto:L-marks@northwestern.edu" target="_blank">L-marks@northwestern.edu</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">For some years I have been working on better optimizers and mixers,<br>
mainly for Wien2k but I also made a small contribution to QE in the<br>
curvature trapping for your BFGS optimizer for the atom positions. I<br>
have a new algorithm (actually one proposed by Bendt and Zunger in<br>
1983) which is mature enough in Wien2k that it is now the recommended<br>
optimizer -- it simultaneously "mixes" the density and atomic<br>
positions. I am attaching the reprint (which might get filtered out);<br>
it is a bit complicated although the fortran code is not as grim as<br>
one might think. Alas JCTC mangled horribly the nomenclature section<br>
at the end.<br>
<br>
I am interested in exploring how this algorithm would work in other<br>
codes. Unfortunately I do not have the time (or money) to invest in<br>
learning all the internal details of other codes. Perhaps someone<br>
would be interested in collaborating to try and implement it in QE?<br>
<span class="HOEnZb"><font color="#888888"><br>
--<br>
Professor Laurence Marks<br>
Department of Materials Science and Engineering<br>
Northwestern University<br>
<a href="http://www.numis.northwestern.edu" target="_blank">www.numis.northwestern.edu</a> 1-847-491-3996<br>
"Research is to see what everybody else has seen, and to think what<br>
nobody else has thought"<br>
Albert Szent-Gyorgi<br>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div dir="ltr">------------------------------------------------------------------------------------------------------------<div>Yue-Wen FANG, PhD candidate<br>
<div><a href="http://clpm.ecnu.edu.cn/" style="font-family:arial,sans-serif;font-size:14px;background-color:rgb(255,255,255)" target="_blank">Key Laboratory of Polar Materials and Devices, Ministry of Education</a><br style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;background-color:rgb(255,255,255)">
<div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;background-color:rgb(255,255,255)"><a href="http://english.ecnu.edu.cn/" target="_blank">East China Normal University </a></div><div style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:14px;background-color:rgb(255,255,255)">
I will persist until I succeed!</div></div><div><br></div><div><br></div></div></div>
</div></div>