Well, I also like the way the tasks are distributed, it is conceptually very clear. I know a different code that saves a DOS file after a band calculation and the newbies come to me with strange peaks in DOS that are caused by a flat band along a line. <br>
Calling dos from pw.x or pw from dos.x masks that conceptual clarity. However, we have to be practical and run the frequent calculations as easily as possible. I would prepend a nscf calculation with "standard options" , and give warning in the otput file that non-standard options can be done doing the nscf calculation separately.<br>
<br>Also, I would alway make pw.x to write the self-consistent DOS in a file after an scf calculation, no matter how coarse is the k-points grid. I find this useful for checking purposes (e.g. to know if an impurity have levels in the gaps). Also, for simple metals the k-points grid needed to have converged energies and forces also is enough to have a good DOS. Then let the user the choice to do post processing if want a DOS with an occupation scheme different than the SCF. I would put this file in the .save directory and name it prefix.scfdos or something like that.<br>
<br>Boris, thank for your script. I will soon test it. Maybe it can be embedded in PWGUI.<br><br>Best regards<br>Eduardo <br><br>---------- Mensaje reenviado ----------<br><div class="gmail_quote"><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
From: Paolo Giannozzi <<a href="mailto:giannozz@democritos.it">giannozz@democritos.it</a>><br>To: PWSCF Forum <<a href="mailto:pw_forum@pwscf.org">pw_forum@pwscf.org</a>><br>Date: Thu, 26 Feb 2009 10:34:30 +0100<br>
Subject: Re: [Pw_forum] band and dos input files in xcrysden<br><br>
On Feb 21, 2009, at 17:05 , Eduardo Ariel Menendez Proupin wrote:<br>
<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Let me remind how is the process to obtain the DOS. It has three calculations<br>
and 3 input files<br>
<br>
pw.x < <a href="http://si.scf.in" target="_blank">si.scf.in</a> > si.scf.out # self consistent<br>
pw.x <<a href="http://si.dos.in" target="_blank">si.dos.in</a> > si.dos.out # non selfconsistent dense k-points mesh and a few options<br>
dos.x <<a href="http://si.dos2.in" target="_blank">si.dos2.in</a> > si.dos2.out # postprocessing<br>
</blockquote>
<br>
Hi Eduardo, the issue you raise is a serious one and requires some though.<br>
Right now several standard calculations in q-e are clumsy because they<br>
require separate steps. While I think that it is a good idea to keep separate<br>
steps separate, I also think that at least the most common calculations might<br>
be streamlined. I am not convinced that the PWGui is the right tool for this,<br>
though, at least not in the present form (a tool to produce input data).<br>
The ideal solution would be the usage of a high-level scripting language like<br>
python to "glue" the various pieces together, but this is highly nontrivial<br>
(at least for me and for 99% of q-e users).<br>
A simpler option could be to collapse some calculations into the same executable:<br>
for instance<br>
- add a call to dos after a nscf calculation in pw.x,<br>
add a call to bands after a bands calculation in pw.x<br>
or<br>
- prepend a nscf calculation to dos.x,<br>
prepend a band calculation to bands.x<br>
Suggestions are welcome<br>
<br>
Paolo<br>
---<br>
Paolo Giannozzi, Democritos and University of Udine, Italy<br>
<br>
<br>
<br>
<br></blockquote></div><br>