[Pw_forum] Re: Help generating Pd pseudo

[Lucas Fernandez Seivane]

Hi Derek

Thanks for your reply. I was aware of some of the problems you
comment, but mine is that in fact this pseudo gives always a magnetic
ground state, even at lattice constants more compressed that
experimental one! I will check with nlcc!

Best regards

Lucas Fernández Seivane
Ph.D. student, Universidad de Oviedo, Spain

On 3/30/06, stewart at cnf.cornell.edu <stewart at cnf.cornell.edu> wrote:
> Hi Lucas,
>
>    Palladium has a high magnetic susceptibility and sits right on the edge
> of magnetism.  I have been looking at nanostructures based on Pd and I have
> found that the pseudopotential choice is very crucial in determining whether
> you get the correct non-magnetic fcc ground state.  All pseudopotentials
> predict that as you expand the palladium lattice, you should see a
> transition to a magnetic state.
>
> However, of the four pseudopotentials available on the PWscf website, only
> the Perdew-Zunger (LDA) with non-linear core correction and the semi-core d
> valence state (Pd.pz-nd-rrkjus.UPF) gives the correct non-magnetic fcc
> ground state.  All varieties of GGA psp predict a ground magnetic state,
> most likely due to the fact that they slightly overestimate the lattice
> constant.  This problem is something that has been observed over a wide
> range of codes including Siesta, VASP, and Wien2k.  See the comment by S.
> Alexendre et al., PRL 96 079701 (2006) for more details.
>
> For your calculations, I would suggest including non-collinear core
> corrections and seeing if this helps.
>
> Best regards,
>
> Derek
>
>
>
> Lucas Fernandez Seivane writes:
>
> > Hi to all in the list
> >
> > I am trying to generate a fully relativistic pseudo for Pd. But with
> > these parameters I always get magnetic Pd! Do you see anything wrong
> > in the input?
> >
> >
> > Best wishes to all
> > Lucas Fernández Seivane
> > Ph.D. student, Universidad de Oviedo, Spain
> >
> >  &input
> >         title='Pd',
> >         zed=46.0,
> >         rel=2,
> >         iswitch=3,
> >         rlderiv=2.50,
> >         eminld=-3.0,
> >         emaxld=3.0,
> >         deld=0.02,
> >         nld=5,
> >         config='[Kr] 4d9 5s1 5p0',
> >         dft='LDA'
> >  /
> >  &inputp
> >         pseudotype=3,
> >         lloc=0,
> >         file_pseudopw='PdrelNN.RRKJ3',
> >         nlcc=.false.
> >  /
> > 7
> > 4D  3  2  4.00  0.00  1.80  2.40  1.50
> > 4D  3  2  0.00 -0.20  1.80  2.40  1.50
> > 4D  3  2  5.00  0.00  1.80  2.40  2.50
> > 4D  3  2  0.00 -0.20  1.80  2.40  2.50
> > 5P  2  1  0.00  0.00  2.40  2.40  0.50
> > 5P  2  1  0.00 -0.00  2.40  2.40  1.50
> > 5S  1  0  1.00  0.00  2.40  2.40  0.50
> > _______________________________________________
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>
>
>
> ################################
> Derek Stewart, Ph. D.
> Scientific Computation Associate
> 250 Duffield Hall
> Cornell Nanoscale Facility (CNF)
> Ithaca, NY 14853
> stewart (at) cnf.cornell.edu
> (607) 255-2856
>
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