[Wien] Re: Charge for spin-polarized case

[Peter Blaha]

No.
You would mst likely want to ADD spin-up and dn and subtract the atomic 
densities from that.

>   thank you for your prompt response. Should I do the same thing if I want compute the "difference densities" to see chemical bonding (DIFF option in case.in5)
>    
>    
>   P. Blaha wrote:
>    
>   In spinpolarized cases x lapw5 -up   reads mandatory from case.clmvalup.
> It also tries to read from case.clmvaldn, and if this file is present, it
> subtracts (or adds) the density of these two files.
> Thus you can easily calculate the "total valence density" (the sum of up+dn)
> or the "spin-density (which is the difference of up-dn)
> 
> Somebody wanted to plot ONLY the spin-up density. In this case 
> mv case.clmvaldn case.clmvaldn_save      (or similar).
> x lapw5 -up     reads now ONLY clmvalup and thus plots the spin-up density.
> 
> And vice versa for spin-dn ...
> 
> >   I'm using WIEN2k_04 for plot the difference charge density for spin-polarized calculation. I searched the mailing and I found this mail from Prof. Blaha in response the an email from a fellow user (see below). What does Prof. Blaha mean when he says rename case.clmvalup (dn)  (again see mail below) ? If I do that, I get an error since case..clmvalup (dn) is needed in up uplapw5.def
> >    
> >   BEGIN
> >   =========
> >   P. Blaha wrote:
> >    
> >   When you do a standard charge density plot in WIEN for a spin polarized 
> > case, you will always get the spin-density (as default).
> > 
> > In order to calculate spin-up or dn densities seperately, you need to 
> > rename case.clmvaldn (or up) to something else (a file with this name 
> > must not be present).
> > 
> > 
> > 
> > > Recently I have studied magnetic systems using spin polarized calculation.
> > > When I calculate the charge density or spin density contours for spin up and
> > > spin down population. I find them the same. But when I calculate the
> > > electronic DOS for spin up and dow, they are different, which agree well with
> > > the physical interpretaion. I have not find in the litterature the
> > > interpreation to this result. 
> > > 
> > > Some one can hel me to understand the physical origin of this. I hoe that it
> > > is not a bug in the w2web presentation. 
> > > 
> > > best regards,
> > > 
> > > souraya
> >    
> >   =========
> >   END
> >    
> >    
> > 
> 
> 


                                      P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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