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["Javad hashemifar" <jhashemifar@gmail.com>]

Many Thanks for your kind answers and explanations. In addition to the
PAW method I will try with comment of Martin about reduction of
r_cut(d) in psudopotential of Cr. I will inform you about the results.
regarding the question of zzzhong: I have not compared yet the
theoretical lattice constant of CrAs in Wien2k and Abinit, but I will
do that after finding my appropriate pseudopotential for Cr. I am
currently focusing on the GGA theoretical lattice parameter of CrAs
(calculated by wien2k).

Kind regards
Javad Hashemifar



On 12/8/06, Martin Fuchs <fuchs@fhi-berlin.mpg.de> wrote:
> Dear Javad,
>
> just a comment on the Cr pseudopotential:
>
> For spin-polarized systems, a partial core
> density must be included. Smaller core
> cutoff radii (=larger core density) should
> give more realistic results (=closer to all
> electron). See the chapter on Mn in the
> tutorial distributed with the fhipp package.
> For Cr rc=1 bohr should be o.k.
>
> In the 3d elements also the shape of the
> d pseudowavefunction (your DOS peaks come
> from these?) is important (spin polarization
> happens mainly close to the Cr sites?). For
> soft TM potentials the pseudowfct. differs
> a lot from the full potential one, e.g. its
> maximum is shifted to larger r. Small
> core radii are thus preferred, the
> default rcut_d=2+x is too large, I'd
> try as small as you can afford (smaller
> rcut_d implies higher plane wave cutoff).
> Again, see the tutorial on what to expect.
>
> Best wishes,
> Martin
>
>
>
>
> Javad hashemifar wrote:
>
> > Dear Abinit users
> >
> > I am a new user of abinit and interested to study the ferromagnetic
> > properties of CrAs in zincblend structure. As you may have heard about
> > it, a couple of years ago it was found that CrAs in semi stable
> > zincblend structure shows half metallic ferromagnetic properties.
> > As it is recommended for every pseudopotential calculation, at the
> > start of my study I am checking the reliability of the available
> > pseudopotentials by comparing the results of Abinit by a full
> > potential package (Wien2k).
> > Please find as an postscript attachment the result of my comparison
> > between the spin resolved DOS of CrAs in Abinit and Wien2k. As it is
> > clear in the figure, the obtained DOS by using the norm conserving
> > pseudopotentials (available in FHI homepage) is considerable different
> > to the DOS of Wien2k, specially in the down channel.
> > But we found that after applying core correction the DOS of Abinit
> > becomes much more similar to the DOS of Wien2k, however still there
> > are some nontrivial differences. The splitting of up and down valence
> > states in Wien2k is higher than Abinit. In order to remove this small
> > (but important) difference, I modified some parameters (increasing
> > number of kpoints, cutoff energy, and decreasing the core correction
> > radius), but these modifications have almost no effect on DOS (please
> > see the attached figure).
> > I would appreciate if any body explain me what is the source of
> > difference between DOS of Abinit and Wien2k.
> >
> > Thanks in advance
> > Javad Hashemifar
> >
>
> --
> Martin Fuchs
> Phone:  +30 8413 4802           | Fritz-Haber-Institut der MPG
> Fax:    +30 8413 4701           | Faradayweg 4-6
> E-Mail: fuchs@fhi-berlin.mpg.de | D-14195 Berlin (Germany)
>
> 1-0.0735-11600-23.05


--
======================================
Seyed Javad  Hashemifar,    Ph.D.
[current:]
Tel:+49-203-3794743        Fax:+49-203-3794742
Fachbereich Physik (AG Kratzer), Universitat Duisburg-Essen
47048 Dusiburg, Germany
[permanent:]
Tel:  +98-311-3912375       Fax: +98-311-3912376
Physics Department, Isfahan University of Technology
84156 Isfahan, Iran
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