Hi Alberto, Thank you for the quick reply!
What you say makes sense, but doesn't it render the plot_num=21 feature kind of useless then?
BTW, using the plot_num=0 for the pseudo charge density also doesn't give me reasonable results, possibly for the same reason. I guess I need finer grids even for that case?
Ultimately I am interested in the total charge density of my system (including positive charges from the cores); Am I correct that this is difficult to obtain using QE?
Cheers! On 10/2/18 11:37 AM, Alberto Otero de la Roza wrote:
Hi Jan, That is normal for the all-electron density. The density peaks at the nuclei are very steep, so they are poorly represented by a uniform grid and consequently the cube doesn't integrate to the correct number of electrons. You can try to make the grid finer but for most systems that won't help very much because you would need an unreasonable number of grid points to converge it. Best, Alberto -- Dr. Alberto Otero de la Roza Department of Physical and Analytical Chemistry, University of Oviedo * Jan Oliver Oelerich <[email protected]> [2018-10-02 11:28:05 +0200]:Hi QE users, I need the total charge density (including core electrons) and calculated it using pp.x's `plot_num=21` method after a converged SCF calculation. (See below for the pw.x and pp.x input files). Summing up the values of the `density.cube` file and multiplying the result with the volume element (dV=V/(96*96*180), V in bohr^3) gets me nothing even close to the expected value of 76 electrons. (I get 2.7..) What am I missing here? Are my grids too small or is it something about the units that I got wrong? Thanks and cheers, Jan Oliver Oelerich -------pw.x---------- &CONTROL calculation = 'scf', prefix = 'GaN', pseudo_dir = '/opt/QEPseudos/pslibrary.1.0.0/pbe/PSEUDOPOTENTIALS', outdir = './out', wf_collect = .TRUE., / &SYSTEM ecutwfc = 30.0 ntyp = 2 nat = 4 ibrav = 0 nr1 = 96 nr2 = 96 nr3 = 180 / &ELECTRONS / ATOMIC_SPECIES Ga 69.723 Ga.pbe-dn-kjpaw_psl.1.0.0.UPF N 14.007 N.pbe-n-kjpaw_psl.1.0.0.UPF K_POINTS automatic 6 6 4 0 0 0 CELL_PARAMETERS angstrom 3.18600000000000 0.00000000000000 0.00000000000000 -1.59300000000000 2.75915693645722 0.00000000000000 0.00000000000000 0.00000000000000 5.18600000000000 ATOMIC_POSITIONS angstrom Ga 0.0000000000 0.0000000000 0.0000000000 N 0.0000000000 1.8394379576 0.6440642113 Ga 0.0000000000 1.8394379576 2.5930000000 N 0.0000000000 0.0000000000 3.2370642113 -------pp.x------------ &inputpp prefix = 'GaN' outdir = './out' filplot = 'electron_density.dat' plot_num = 21 / &plot nfile = 1 filepp(1) = 'electron_density.dat' weight(1) = 1.0 iflag = 3 output_format = 6 fileout = 'density.cube' / -- Dr. Jan Oliver Oelerich Philipps-Universität Marburg Faculty of Physics and Material Sciences Center Addr.: Room 02D35, Hans-Meerwein-Straße 6, 35032 Marburg, Germany Phone: +49 6421 2822260 Semiconductor Theory, Department of Physics Addr.: Room 01001, Mainzer Gasse 33, 35032 Marburg, Germany Phone: +49 6421 2824335 Mail : [email protected] Web : http://academics.oelerich.org _______________________________________________ users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users_______________________________________________ users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
-- Dr. Jan Oliver Oelerich Philipps-Universität Marburg Faculty of Physics and Material Sciences Center Addr.: Room 02D35, Hans-Meerwein-Straße 6, 35032 Marburg, Germany Phone: +49 6421 2822260 Semiconductor Theory, Department of Physics Addr.: Room 01001, Mainzer Gasse 33, 35032 Marburg, Germany Phone: +49 6421 2824335 Mail : [email protected] Web : http://academics.oelerich.org _______________________________________________ users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
