[Pw_forum] How to calculate magnetization density when SOC is on

[Andrea Dal Corso]

On Mon, 2011-01-17 at 11:48 +0100, Gabriele Sclauzero wrote:
> Hi Soroush
> 
> On 01/15/2011 02:50 PM, soroush pakseresht wrote: 
> > Hi everybody, 
> > 
> > 
> > Can anybody tell me how I can calculate the magnetization
> > M=M(Mx,My,Mz) for a system with spin-orbit coupling. 
> 
> Usually the three components of the total non-collinear magnetization
> are printed at the end of the calculation, e.g.
> 
>      The total energy is the sum of the following terms:
> 
>      one-electron contribution =   -90.33299784 Ry
>      hartree contribution      =    49.63924278 Ry
>      xc contribution           =   -28.28794844 Ry
>      ewald contribution        =    -0.25003496 Ry
>      smearing contrib. (-TS)   =    -0.00000505 Ry
> 
>      total magnetization       =     0.00     0.00     0.11 Bohr
> mag/cell
>      absolute magnetization    =     0.11 Bohr mag/cell
> 
> 
> 
> > I'd like to know the total value of Mx, My, Mz for each band at a
> > given kpoint. 
> > 
> 

You can use the program bands.x with the flag lsigma=.true. .
Please check INPUT_BANDS for more info.

HTH

Andrea 


> What you're asking for is somehow the magnetization carried by the
> individual KS eigenstates. I think that for this you'll have to modify
> the PWscf or PostProc code. For instance you could start from pp.x and
> modify the option plot_num=7 by performing the integral of the
> resulting spin-density over the whole unit cell (should be the sum
> over the FFT components, perhaps multiplied by some normalization
> factor).
> Maybe it's easier to implement this directly in PWscf. At the moment
> the code first computes the total spin-density (which is the sum over
> bands and k-points of the individual KS densities) in sum_band.f90
> (search for 'domag') and then the magnetization by integrating the
> components of the spin-density (see compute_magnetization in
> PW/electrons.f90). You can modify sum_band.f90 by adding a call to a
> function analogous to compute_magnetization but for each single KS
> state.
> 
> 
> HTH
> 
> GS
> 
> > 
> > 
> > Thanks
> > 
> > -- 
> > Soroush Pakseresht 
> > Advanced Science Institute (RIKEN)
> > Saitama-Japan
> > 
> > 
> > 
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum at pwscf.org
> > http://www.democritos.it/mailman/listinfo/pw_forum
> >   
> 
> 
> -- 
> 
> Gabriele Sclauzero, EPFL SB ITP CSEA
> PH H2 462, Station 3, CH-1015 Lausanne
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-- 
Andrea Dal Corso                    Tel. 0039-040-3787428
SISSA, Via Bonomea 265              Fax. 0039-040-3787249
I-34136 Trieste (Italy)             e-mail: dalcorso at sissa.it