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

[Peter Blaha]

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