<div dir="ltr">Dear Sathya,<br><br>Please go through the pages in the following link:<br><br><a href="http://www.quantum-espresso.org/wiki/index.php/Tutorials_and_Examples">http://www.quantum-espresso.org/wiki/index.php/Tutorials_and_Examples</a>.<br>
<br>It will help you a lot with the basics involved in performing a calculation.<br><br>As far as finding the cell parameters are concerned, you can do it in two ways using pw.x:<br><br>(1) using calculation='vc-relax', which is quite tricky to use <br>
<br>(2) by relaxing manually, do "relax" or "scf" cal. for different sets of cell parameters ( ususally around +/- 3-4 % of the experimentally one). Use ev.x to fit the data to some equation of state and obtain the optimized values of cell parameters.<br>
<br>With regards,<br>Prasenjit.<br><br><div class="gmail_quote">2008/7/28 sathya subramanyan <span dir="ltr"><<a href="mailto:sathya_sheela1985001@rediffmail.com">sathya_sheela1985001@rediffmail.com</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<p>
Dear All,<br>
I know this is a very basic question but I would like to know which example; Example03 or VCSexample should be used to optimize any structure. Example03 gives the optimized positions but not the cell dimensions while VCSexample(runs for more than a day) gives both the optimized cell dimensions and cell positions (but not close to the experimental ). Please do help. Thank you in advance. <br>
</p>
SATHYA SHEELA.S
<br>
Grad. Student
<br>
Department of Physics
<br>
National Institute of Technology
<br>
Tiruchirapalli - 620015
<br>
India<br><br>
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