[Wien] Choice of exchange correlation-potential for LDA+U

[Gerhard Fecher]

Dear Peter,
I think if using LDA instead of LSDA one might need to change the values of
J to smaller ones as the count of the electrons is different in the spin and non-spinpolarized cases.
I recently asked Anisimov and he confirmed that he counts only half (one spin direction
only) if calculating J from the Slater integrals.
Just for those who are interested in the non-spherical (multipole) terms in LDA+U,
this may be interesting. 

Ciao
Gerhard



-----Ursprüngliche Nachricht-----
Von: wien-bounces at zeus.theochem.tuwien.ac.at im Auftrag von Peter Blaha
Gesendet: Do 24.08.2006 07:55
An: A Mailing list for WIEN2k users
Betreff: Re: [Wien] Choice of exchange correlation-potential for LDA+U
 
It should be used with option 1. This is LDA (and not LSDA), i.e. all the 
spinpolarization would come freom the LDA+U term, the rest of the electron 
system does not have any spin-dependency in Vxc.

I'd call this an "experimental" LDA+U option; I do Not recommend it for 
general use.

> Thanks for your reply, Saeid! Even though it might not be too critical 
> (perhaps someone disagrees), I would still like to be sure what the 
> intention of the usersguide authors really is. Is it that one should use 
> option #5 (Perdew and Wang 92) or option #1 (Moruzzi, 
> Janak,Williams(78)) together with the LDA+U(HMF) method?
> 
> Any comments/suggestions are welcome!
> 
> Thanks for your replies!
> 
> Best regards,
> Thomas Claesson
> 
> Saeid Jalali wrote:
> 
> > 
> > Hi,
> > I agree that this statement of the usersguide is not so clear, since in 
> > one side after running lstart a new wien user reads:
> > SELECT XCPOT:
> > recommended: 13: GGA (Perdew-Burke-Ernzerhof 96)
> >                         5: LSDA
> >                       14: GGA (Perdew-Wang 91)
> > and on the other hand there is no option 5 in the vxclm2.
> > 
> > However, this is not the case for you, as you have already nicely 
> > distinguished the above option 5 from what is stated in the usersguide, 
> > ...with the LDA (not
> > LSDA) exchange-correlation potential....
> > 
> > The statement in the usersguide seems to emphasis on the double counting 
> > (dc) term, see 
> > http://www.wien2k.at/reg_user/textbooks/orbital_potentials.ps .
> > However, this, dc, seems also not be so serious, because of the 
> > following Pavel's comment:
> > http://zeus.theochem.tuwien.ac.at/pipermail/wien/2004-November/004073.html
> > 
> > 
> > Thomas Claesson <tcl at kth.se> wrote:
> > 
> >     Dear Wien users and developers!
> > 
> >     In the usersguide, page 78, you find this text about the LDA+U(HMF)
> >     method:
> > 
> >     LDA+U(HMF) - in addition the Hubbard model in the mean field
> >     approximation, as introduced by Anisimov et al. 1991 is also
> >     implemented. Note, however, that it is to be used with the LDA (not
> >     LSDA) exchange-correlation potential in spin polarized calculations!
> > 
> >     I am not sure that I understand the meaning of the last sententence
> >     correctly. Does it mean that I only can use option #5 ("5 Perdew and
> >     Wang 92, reparameterization of Ceperly-Alder data, the
> >     recommended LDA option", see usersguide page 77) when I choose
> >     exchange-correlation potential in case.in0? Which of the available
> >     options is the LSDA-option referred to above to not use in this case?
> >     Option #1 perhaps?
> > 
> >     Thanks for your replies!
> > 
> >     Best regards,
> >     Thomas Claesson
> > 
> > 
> > 
> > 
> >     _______________________________________________
> >     Wien mailing list
> >     Wien at zeus.theochem.tuwien.ac.at
> >     http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> > 
> > 
> > 
> > 
> > Sincerely yours,
> > S. Jalali.
> > /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
> > Saeid Jalali Asadabadi,
> > Department of Physics, Faculty of Science,
> > University of Isfahan (UI), Hezar Gerib Avenue,
> > 81744 Isfahan, Iran.
> > Phones:
> > Dep. of Phys.  :+98-0311-793 2435
> > Office              :+98-0311-793 2430
> > Fax No.           :+98-0311-793 2409
> > E-mail             :s_jalali_a at yahoo.com
> > www                :http://www.ui.ac.ir
> > /_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
> > 
> > ------------------------------------------------------------------------
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> > 
> > 
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                                      P.Blaha
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