[Pw_forum] 3D charge density with Xcrysden

[Giovanni Cantele]

majid yazdani wrote:
> *Dear all users,*
> *I want to know how could I visualize a 3D charge density plot with 
> xcrsden.?*
> ** 
> *Besr regards,*
> *Majid*
> *Department of Physics, University of Kashan, Iran.*
> ------------------------------------------------------------------------
>
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>   

First step should, of course, to generate a file with Xcrysden format 
(http://www.xcrysden.org/doc/XSF.html#scalar-field)
containing information on
your crystal (lattice, atomic positions), the spatial grid on which the 
charge density is calculated
and the values of the charge density on the points of that grid.
This is done using the post-processing tools of Quantum-Espresso, 
documented in Doc/INPUT_PP.txt
Basically, you should:
i) make an scf run, using pw.x ;
ii) post-process your results, using pp.x
the input file of the latter should contain both the &INPUTPP and the 
&PLOT (see the above mentioned
doc for further reference)


Then, you'll end up with  a *.xsf file, which can be directly read by 
XCrysDen.

Here there is a description on how to load the file and the charge 
density data inside:
http://www.xcrysden.org/doc/density.html

Here there is a description on how to change some parameters controlling 
the display of the isosurfaces:
http://www.xcrysden.org/doc/isocontrol.html

Once all this is done, you may also play with 2D cuts of you charge 
density (projection onto a plane),
which are directly handled by XCrysDen.

Giovanni

-- 



Dr. Giovanni Cantele
Coherentia CNR-INFM and Dipartimento di Scienze Fisiche
Universita' di Napoli "Federico II"
Complesso Universitario di Monte S. Angelo - Ed. 6
Via Cintia, I-80126, Napoli, Italy
Phone: +39 081 676910
Fax:   +39 081 676346
E-mail: giovanni.cantele at cnr.it
        giovanni.cantele at na.infn.it
Web: http://people.na.infn.it/~cantele
Research Group: http://www.nanomat.unina.it