[Pw_forum] MnPd Bulk

Eyvaz Isaev eyvaz_isaev at yahoo.com
Wed Dec 3 00:20:32 CET 2008


Hi Derek,

--- On Tue, 12/2/08, Derek Stewart <stewart at cnf.cornell.edu> wrote:

> Some other groups have also observed this problem using > other techniques (localized orbitals, Siesta I believe). 
 
Another example is so-called Exact Muffin-Tin Orbitals (EMTO) code which is based on Green's functions.
Of course, the physics should not depend on a particular choice of the method to solve the Kohn-Sham equations, if it is developed (and programmed) correctly. 
In this particular case with Pd (you know, of course) the problem is connected to location of the Fermi level in the electronic DOS with quite high N(E_F), in the vicinity of the Stoner criterion IxN(F_F)>1 with I is being intra-atomic exchange integral almost independent on crystalline structure and atom type. If one slightly changes (enlarges) the lattice parameter then the criterion is fulfilled and Pd becomes magnetic.

The only difference might be for so called DMFT-codes, but it is beyond DFT.

Bests,
Eyvaz.
 
> 
>  
> 
> Eyvaz Isaev writes: 
> 
> > Hi, 
> > 
> > Mn and Pd are quite interesting metals. You can find a
> magnetic moment on Pd atoms depending on its local
> environment and slightly larger lattice parameters. 
> > This has a sense as you used GGA (PBE) base
> pseudopotentials which tend to give larger lattice parameter
> 
> > inducing magnetism for Pd atoms, at least. You can
> carry out calculations with LDA-based PsPs.
> > Try also usin the same lattice parameters as in the
> paper you cited. 
> > 
> > Hope this helps. 
> > 
> > Bests,
> > Eyvaz. 
> > 
> >
> -------------------------------------------------------------------
> > Prof. Eyvaz Isaev, 
> > Theoretical Physics Department, Moscow State Institute
> of Steel & Alloys, Russia, 
> > Department of Physics, Chemistry, and Biology (IFM),
> Linkoping University, Sweden 
> > Condensed Matter Theory Group, Uppsala University,
> Sweden 
> > Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se,
> eyvaz_isaev at yahoo.com 
> > 
> > 
> > --- On Tue, 12/2/08, Salvador Meza Aguilar
> <smeza at uas.uasnet.mx> wrote: 
> > 
> >> From: Salvador Meza Aguilar
> <smeza at uas.uasnet.mx>
> >> Subject: [Pw_forum] MnPd Bulk
> >> To: pw_forum at pwscf.org, "DEMANGEAT
> Claude" <demangea at fresnel.u-strasbg.fr>,
> "Bernard M'Passi Mabiala"
> <mpassi_b at yahoo.com>
> >> Date: Tuesday, December 2, 2008, 9:17 PM
> >> I'm investigating the magnetic properties of
> MnPd
> >> ordered alloys
> >> on Co(001) and Co(111) fcc, using PWscf version
> 3.2 
> >> 
> >> I have some questions about the obtained results. 
> >> 
> >> I try to find the values reported in the following
> paper:
> >> Journal of Alloys and Compounds 415, 31-37 (2006),
> in the
> >> table IV,
> >> the values for magnetic moments for Mn and Pd
> atoms in each
> >> magnetic configuration. I found dead magnetic
> moments for
> >> each
> >> magnetic configuration. I have several results
> with MnPd on
> >> Co substrate; with
> >> non zero magnetic moments for Mn and Pd atoms. 
> >> 
> >> Which is the problem? I attach the input files. 
> >> 
> >> 
> >> --
> >>
> -----------------------------------------------------------------
> >> Dr. Salvador MEZA AGUILAR
> >> Escuela de Ciencias Fisico-Matematicas
> >> Universidad Autonoma de Sinaloa
> >> Av. de las Americas y Blvd. Universitarios
> >> Ciudad Universitaria
> >> 80010 Culiacan Sinaloa
> >> Mexico
> >> Tel./Fax +52 6677 15 64 12 ext 114
> >> Tel./Fax +52 6677 16 11 54 ext 114
> >> e-mail: smeza at uas.uasnet.mx
> >>
> -----------------------------------------------------------------
> 
> >> 
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> >  
> > 
> >       
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>  
> 
> 
> ################################
> Derek Stewart, Ph. D.
> Scientific Computation Associate
> http://www.people.cornell.edu/pages/das248/
> 250 Duffield Hall
> Cornell Nanoscale Facility (CNF)
> Ithaca, NY 14853
> stewart (at) cnf.cornell.edu
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