Dear <span>Stefano</span><br>Thanks for your answer<br>Why they used this kind of lattice? there are many another example like this.<br><br>Mohsen Modaresi<br><br><div class="gmail_quote">On Thu, Nov 26, 2009 at 6:26 PM, Stefano de Gironcoli <span dir="ltr"><<a href="mailto:degironc@sissa.it">degironc@sissa.it</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;">Dear mohsen modaresi<br>
<br>
you can describe an fcc crystal in an FCC bravais lattice with one atom<br>
per cell or in a Simple Cubic cell with 4 atoms per cell or in a<br>
tetragonal cell with 2 atoms per cell or in many other equivalent ways.<br>
Why it is done using tetragonal lattice in that particular example I<br>
don't know but it may be due to the need of using some particular<br>
orientation or orthonormal Bravais vectors or some other reason.<br>
Hope this helps,<br>
<br>
stefano.<br>
<div class="im"><br>
mohsen modaresi wrote:<br>
> Hi dear users<br>
> I read Ex.12 and run it, In the input file for Al (<a href="http://al.scf.in" target="_blank">al.scf.in</a><br>
</div>> <<a href="http://al.scf.in" target="_blank">http://al.scf.in</a>> ) i see this part<br>
<div class="im">> ibrav = 6,<br>
> celldm(1) =5.3,<br>
> celldm(3) =1.414,<br>
> But we konw that Al has F.CC structure, Why they set ibarav=6 not 2, I<br>
> faced with this problem in example 11 in the Want package.<br>
> Thanks for answers<br>
><br>
> Mohsen Modaresi<br>
> Msc. Student of Solid State Physics,<br>
> Department of Physics,Ferdowsi University of Mashhad,<br>
> Iran.<br>
><br>
</div>> ------------------------------------------------------------------------<br>
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