-----Original Message----- From: Eduardo Ariel Menendez Proupin <[email protected]> To: pw_forum at pwscf.org Date: Mon, 9 Jul 2012 09:44:20 +0200 Subject: Re: [Pw_forum] HOMO,LUMO isosurface, USPP or NCPP?
> Dear Yavar > > USPP and NCPP are mathematical methods to approximate the solution of > the > same physical problem. Hence, there must be no physically different > results, unless one of the pseudopotentials is faulty. Both types of > pseudopotentials have cutoff radii, which are larger for NCPP than for > USPP. The wavefunctions computed with any pseudopotential should be > equal > to the all-electron wavefunctions in the spatial region outside the > spheres > centered at each atom with spheres radii equal to the cutoff radii of > the > corresponding pseudopotential. Inside any sphere, the wavefunctions are > different and are meaningless. To have the correct wavefunctions inside > the > spheres you have any of the following options a) all-electron > calculations > (with a different code,e.g. ADF, Gaussian, LMTO, etc), b) use a PP with > a > smaller cutoff radius (and larger ecutrho and ecutwfc), c) use PAW > (projector augmented wave). > > sincerely yours > > > Eduardo Menendez Proupin > Departamento de Qu?mica Fisica Aplicada > Facultad de Ciencias > Universidad Aut?noma de Madrid > 28049 Madrid, Spain > Phone: +34 91 497 6706 > > > > Dear QE users. > > > > > > I want to plot HOMO, LUMO isosurfaces. what is the physical origin > > of difference between results from choosing USPP with NCPP? > > Thanks in advance. > > > > > > ------------------------------------------- > > Yavar Taghipour Azar > > PhD Student > > Physics Group, AEOI > > Tehran-Iran > > > > Email: ytaghipour at aeoi.org.ir > > Phone: +98 (0) 21 82064556 > > ----------------------------------------------------------- > > > > > > > > > > > -- -------------- next part -------------- An HTML attachment was scrubbed... URL: http://www.democritos.it/pipermail/pw_forum/attachments/20120710/c54a5751/attachment-0001.htm
