[Pw_forum] HOMO,LUMO isosurface, USPP or NCPP?

[Yavar Taghipour Azar]

-----Original Message-----
From: Eduardo Ariel Menendez Proupin <eariel99 at gmail.com>
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 Química Fisica Aplicada
> Facultad de Ciencias
> Universidad Autónoma 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
> > -----------------------------------------------------------
> >
> >
> >
> >
> >
> --
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