[Wien] How to subtract a particular orbital character from a valence electronic density?

[Martin Gmitra]

Dear all,

Thanks for your replays. The system we study is a
semiconductor/ferromagnet heterostructure (slab) with spin-orbit and
spin-polarization included. We think that separation of d and s
orbital contribution to the electronic (density of) states around
Fermi level would help us to understand difference in FMR and lateral
transport experiments. The experiments are differently sensitive to
the two-fold and four-fold symmetry of the system as the number of the
ferromagnet layers grows. We think that the experiments are
differently sensitive to the d and s electrons.

The slab contains many electrons therefore wannierization might be
rather difficult task (thanks to Ellias). The case.sigma subtraction
simply removes symmetric say d orbitals while the quantity of interest
Integral[rho(x,y,z) - rho(y,x,z)]dxdy remains untouched (thanks for
hints to prof. Blaha). The s*d density separation is in our case
crucial, therefore I guess, we can not play with the LM components
(thanks for suggestion to prof. Marks). The other suggestion going
through the lapw2/qtl and patching it to the filvec is not clear for
me. I think that a possible way would be to do an LM decomposition of
the (selected) partial charges and write them to case.clmval. I see in
the code that similar information is stored in help files, or?

Best,
Martin
Uni Regensburg


On Tue, Jul 22, 2014 at 1:25 PM, Peter Blaha
<pblaha at theochem.tuwien.ac.at> wrote:
> I'm not really sure what the purpose of this exercise should be, but anyway:
>
> x lapw2 -all e1 e2
>
> check case.output2 (case.scf2) the :QTLxxx lines, which list the partial
> charges of s,p,d,.. like charge.
>
> Suppose you find on atom 1 0.55 "d-charge" and want to subtract this from
> your density in lapw5, then edit case.inst, put "P" and an occupation of
> 0.55 into the "d"-line of the first atom and produce the case.sigma file.
>
> A difference density plot using lapw5 will show the valence density of the
> selected energy region  minus an atomic d-density of the first atom
> (assuming an occupation of 0.55 electrons).
>
> Note, however, that the 0.55 d-electrons of case.scf2 are only inside the
> atomic sphere, while the "input 0.55" in case.inst is the total occupation.
> You would have to look into case.outputst and find out how many d-electrons
> are within the sphere. While this difference is small for localized 3d
> electrons (and large spheres), it will not work at all for delocalized
> densities of eg. 4s character, ....
>
> Therefore my doubts that such a plot will really give you an interpretable
> information. "Hybridization" is found from partial charges, eg. from partial
> DOS or directly from case.scf2.
>
>
> Am 21.07.2014 15:40, schrieb Martin Gmitra:
>>
>> Dear Wien2k users,
>>
>> I would like to plot valence density (lapw5) in a narrow energy window
>> around Fermi level (calculated by lapw2 -all flag) to which I would
>> like to subtract specific atomic orbital character. Say that the
>> density can be expressed as a combination (due to hybridization) of
>> atomic orbitals rho(r)=A(r) s + B(r) p + C(r) d + ..., where the
>> coefficients A(r), B(r), C(r), ... reflect hybridization. My case
>> would be to subtract, say d-orbitals as rho(r) - C(r) d. This differs
>> from modifying case.inst (lstart -sigma flag) and subtracting
>> case.sigma.
>>
>> It looks like to dig in QTL files or can you provide another solution
>> or hint how to start?
>>
>> Best regards,
>> Martin Gmitra
>> Uni Regensburg
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>
> --
> Peter Blaha
> Inst.Materials Chemistry
> TU Vienna
> Getreidemarkt 9
> A-1060 Vienna
> Austria
> +43-1-5880115671
>
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