<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
On 02/05/12 15:46, Carmine Autieri wrote:
<blockquote
cite="mid:19ff11f3-082a-4576-bd73-fdca509d6302@mail.sa.infn.it"
type="cite">
<pre wrap="">Dear Wannier90 users, I kindly ask a simple suggestion.
I am trying to calculate the hopping parameters in a supercell with a large z-axis using wannier90.
The z-axis is 10 times longer than the other axes. Morover, the system is quasi two-dimensional.
I used 10 X 10 X 1 k-points grid. Is it enough for a good estimation of hopping parameters?
The calculation is very expensive for my machine. Do you think that a 8 X 8 X 2 grid should be really better?
thanks
Carmine Autieri
Universita' di Salerno (Italy)
_______________________________________________
Wannier mailing list
<a class="moz-txt-link-abbreviated" href="mailto:Wannier@quantum-espresso.org">Wannier@quantum-espresso.org</a>
<a class="moz-txt-link-freetext" href="http://www.democritos.it/mailman/listinfo/wannier">http://www.democritos.it/mailman/listinfo/wannier</a>
</pre>
</blockquote>
<font face="sans-serif"><br>
I'd use the same k-point sampling as for the DFT calculation to
start with. Plot the bands and check if the wannier bands are in
good agreement. <br>
<br>
I would not use 8x8x2, but 8x8x1 eventually.<br>
<br>
Start with the smallest k-point sampling, check the bands and
increase if the agreement should be better. It will depend on what
you want to do, etc ... of course, you should also pay attention
to the energy windows, disentanglement, spread, etc that are
probably more important than the k-point sampling to get good
bands. Try a smaller system first.<br>
<br>
<br>
Hope this helps,<br>
<br>
Nicolás<br>
</font><br>
<pre class="moz-signature" cols="72">--
Nicolás Lorente
Centro de Investigación en Nanociencia y Nanotecnología
Campus de la UAB
E-08193 Bellaterra
Tel. (+34) 935868410</pre>
</body>
</html>