[Wien] phohtoemission

[Peter Blaha]

The wavefunctions in WIEN2k are quite "complicated" objects.

Anyway, since the free-electron states are very delocalized, I'd probably
start using the pure plane-wave expansion of the wavefunction (and neglect
that this is valid only outside the spheres).

The corresponding coefficients of the PW-expansion of each "orbital"
(each band-index and k-point) are written into case.vector (you have to dig
into the code, since this is an unformatted file), or, alternatively put
WFPRI into case.in1  and it will print them into case.output1.

For a "full" description you need to print the Alm,Blm,Clm calculated in lapw2
and do the integral for the matrixelement over the spheres and the interstital
seperately.

Regards
> With the DFT formalism in WIEN2k code, can you please pin point from where I
> can select/get the initial and final state wavefunctions, say for a system
> like W(100) or Al(100). I can use these wavefunctions for evaluating the
> matrix element for photoemission calculations.My problem is the WAVEFUNCTIONS
> or ORBITALS for a particular symmetry .
> Thanks,
> R.K.Thapa
> =======================
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> ============================
> 
> Lukasz Plucinski wrote:
> 
> > Dear R.K. Thapa,
> > 
> > I am sorry I cannot give you detailed answer, I unfortunately I am very
> > busy recently. Some comments below.
> > 
> >  
> > > (1) I am interested on calculations when electrons are excited from the
> > > initial (valence) to final states (in the vacuum).
> > > (2) What will be the  initial (final) state wavefunctions  from the
> > > wien2k code?
> > >    
> > 
> > You should use valence bands below the Fermi edge as initial states.
> > Within so-called three-step model some calculations of photocurrent are
> > possible. You could use either free-electron or calculated final states.
> > This is, however, only approximation.
> > 
> >  
> > > (3) The type of vector potenial (or electric field for excitation)?
> > > (Is this answerable by wien2k code?)
> > >    
> > 
> > I am not familiar with latest developments of the Wien2k team, but I don't
> > think Wien2k can do this. And I don't think any of popular DFT codes will
> > do this.
> > 
> > Simple solution is to give some weight to the calculated initial and final
> > states and do three-step model thing.
> > 
> > I guess people who do this use some fast empirical tight binding programs
> > to calculate band dispersions. Then they do one-step photoemission
> > calculations. But I am sure there are many ways. It is easy to find
> > publications in popular journals (PRB etc.).
> > 
> > Regards,
> > 
> > Lukasz
> > 
> > 
> >  
> 
> 


                                      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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