Dear Davide,<br><br>Thank you very much for your help.<br>I build the structure my self and I extensionally put the atoms of graphene and BN layers on the top of each other.<br>I have to try also 2 other configurations where BN layers are not centred on the carbon atoms in graphene.<br>
Do you think there is a problem with this configuration? (I am using VMD to visualize the structure).<br>What is wrong in the lattice spacing? What do you mean?<br>Thank you for pointing out that celldim(1) is in bohrradius.<br>
I will correct it. <br>Thanks a lot!<br><br><div class="gmail_quote">On Wed, Dec 16, 2009 at 1:37 PM, Davide Ceresoli <span dir="ltr"><<a href="mailto:ceresoli@mit.edu">ceresoli@mit.edu</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;">
<div class="im">mohamed sabri majdoub wrote:<br>
> Dear all,<br>
><br>
> I am a new user of pwscf.<br>
> I am trying to run a calculation of graphene (1 layer) on BN (2 layers)<br>
> in a supercell with vacuum.<br>
> After that I need to run the same system in the presence of a saw tooth<br>
> potential and get the potential file as output.<br>
> I am not sure that I am doing it the right way. I am using 40 processors<br>
> and I the calculations look very slow to me.<br>
> I really appreciate your help and suggestions for this calculation.<br>
> Thank you in advance for your help.<br>
><br>
> Sab Maj<br>
</div>Dear Sab Maj,<br>
have a look at your structure with XCrysden. There is something<br>
wrong with the lattice spacing. Atoms are sitting on top of each<br>
other. Remember that celldm(1) is in bohrradius, not in angstrom.<br>
This can save you a lot of time!<br>
<br>
Davide<br>
<br>
<br>
--<br>
+----------------------------------------------------------+<br>
Davide Ceresoli <<a href="mailto:ceresoli@mit.edu">ceresoli@mit.edu</a>><br>
DMSE 13-4084<br>
Massachusetts Institute of Technology<br>
77 Massachusetts Avenue<br>
Cambridge, MA 02139-4307<br>
Phone: (617) 253-6026<br>
Mobile:(857) 756-0455, +39-347-1001570(it)<br>
Skype: dceresoli<br>
+----------------------------------------------------------+<br>
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