<html>
<head>
<meta content="text/html; charset=ISO-8859-1"
http-equiv="Content-Type">
</head>
<body bgcolor="#FFFFFF" text="#000000">
Dear Mohnish,<br>
thanks for you answer. I will follow your suggestion and try also
HSE, with a coarser k-point mesh, (indeed with PBE0 the computation
time is quiet large), and I did not know about projwfc.x.<br>
I have a further question concerning the DOS. If I wish to know
about the DOS of my system, which uses the hybrid functional
implementation, am I able to use the projwfc.x? Is'n it a
postprocessing tool?<br>
Thanks,<br>
regards,<br>
Valentina<br>
<br>
Il 04/09/2013 11:18 AM, mohnish pandey ha scritto:
<blockquote
cite="mid:CAMhNW-ckcs6aFOd0z527D5C_0PgMbuzLCpb4vZ9rcJv7Ps4-Cg@mail.gmail.com"
type="cite">
<div dir="ltr">
<div>Hi,<br>
<br>
</div>
As far as I can understand there is no rule. It depends how fine
you want to represent your Fock operator. Normally calculations
of the Fock exchange in expensive, so its not affordable to do
very fine grid calculations So I suggest you start with low
nqx(1, 2, 3) and increase it systematically. Increasing it will
give you better results( I mean converged results, not
necessarily close to experiments). <br>
<br>
Just an advice, PBE0 needs much more high density k-point mesh
for the convergence of Fock exchange since it's a long range
interaction. So you have to do calculations with high density of
k-points. But if you use HSE instead of PBE0 you get away with
coarser k-point mesh since it involves screened exchange
interaction which converges much faster than bare Coulomb
exchange as in PBE0. Regarding to the DOS plot you will find a
nice tutorial on Heither's website, I am pasting the link <a
moz-do-not-send="true"
href="http://www.stanford.edu/%7Ehkulik/www/Tutorials/Entries/2012/1/24_Population_analysis_and_PDOS.html">http://www.stanford.edu/~hkulik/www/Tutorials/Entries/2012/1/24_Population_analysis_and_PDOS.html</a><br>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On Tue, Apr 9, 2013 at 10:05 AM,
"Valentina Dellacà C.R.F. S.C.p.A." <span dir="ltr"><<a
moz-do-not-send="true"
href="mailto:valentina.dellaca@tirocinanti.crf.it"
target="_blank">valentina.dellaca@tirocinanti.crf.it</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div bgcolor="#FFFFFF" text="#000000"> Hi, <br>
I am a Quantum Espresso beginner user, and I am simulating
the Ta2O5 structure, with the employment of the hybrid
functional PBE0. I have some questions : <br>
<br>
- if I choose a k-point grid not in automatic, how should
I pick the nqx1,2,3? Is there a rule?<br>
- when one wishes to have informations (ex. plot) about
the density of states from the scf run, how should I
proceed?<br>
<br>
Thank you, <br>
regards<br>
Valentina
<blockquote type="cite"> <br>
<span class="HOEnZb"><font color="#888888">
<div>-- <br>
<img moz-do-not-send="true" border="0"></div>
</font></span></blockquote>
<span class="HOEnZb"><font color="#888888"> <br>
<br>
<div>-- <br>
<img moz-do-not-send="true" border="0"></div>
</font></span></div>
<br>
_______________________________________________<br>
Pw_forum mailing list<br>
<a moz-do-not-send="true" href="mailto:Pw_forum@pwscf.org">Pw_forum@pwscf.org</a><br>
<a moz-do-not-send="true"
href="http://pwscf.org/mailman/listinfo/pw_forum"
target="_blank">http://pwscf.org/mailman/listinfo/pw_forum</a><br>
</blockquote>
</div>
<br>
<br clear="all">
<br>
-- <br>
Regards,<br>
MOHNISH,<br>
-----------------------------------------------------------------<br>
Mohnish Pandey,<br>
PhD Student,<br>
Center for Atomic Scale Materials Design,<br>
Department of Physics,<br>
Technical University of Denmark<br>
<div>-----------------------------------------------------------------</div>
</div>
</blockquote>
<br>
<br>
<div class="moz-signature">-- <br>
<img src="cid:part7.04070004.04080507@tirocinanti.crf.it"
border="0"></div>
</body>
</html>