Hi,<br>It's not easy to tell unless you do your own test. Try to do your calculation with many different concentration (increase the size of cell) and compare the properties that are well-known (bondlength, formation energy...).<br>
<br>In practice, the concentration of vacancies maybe about ZERO, my point is the large the cell is, the better.<br>Best,<br>D.<br><br><div class="gmail_quote">On Thu, Aug 20, 2009 at 8:27 AM, ali kazempour <span dir="ltr"><<a href="mailto:kazempoor2000@yahoo.com">kazempoor2000@yahoo.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"><table border="0" cellpadding="0" cellspacing="0"><tbody><tr><td style="font-family: inherit; font-style: inherit; font-variant: inherit; font-weight: inherit; font-size: inherit; line-height: inherit; font-size-adjust: inherit; font-stretch: inherit;" valign="top">
<br>Dear All<br>I make 72 atom supercell to study the effect of vacancy on defect formation energy. If I remove one atom do I run vc-relax or relax calculation only? I mean is this concentratio(1/72=0.013) high that affect the lattice constant also or not?<br>
thanks a lot<br> <br>Ali Kazempour<br>
Physics department, Isfahan University of Technology<br>
84156 Isfahan, Iran. Tel-1: +98 311 391 3733<br>
Fax: +98 311 391 2376 Tel-2: +98 311 391 2375</td></tr></tbody></table><br>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Men don't need hands to do things!<br>