[Wien] DOS of slab

[pieper]

Well, the colleague 'desires to obtain the DOS of the just top 
monolayer'.

He (or she) might dodge your "philosophical" question of what space is 
occupied by the topmost layer since the DOS is, after all, not a volume 
density but an energy density. Even if he solves all your questions and 
specifies what space qualifies as topmost layer he still has to decide 
which states contribute how much. Counting electrons in that volume does 
not solve the problem as stated. For example, what about the unoccupied 
DOS above EFermi?

The no less "philosophical" question then is to specify which states he 
wants to give the honor of being part of team 'topmost layer' - then to 
project on them.

And my best wishes for the most difficult part: convince his audience 
that the choice is convincing for the point to be made. ;-)

Martin Pieper


Am 08.05.2017 08:29, schrieb Fecher, Gerhard:
> This might give rise to a "philosophical" question: What is the space
> ocupied by the topmost layer ?
> 
> To use the DOS of the atoms in the "topmost" layer will neglect the
> interstitial between the atoms, that is, the DOS will be not the one
> of the complete
> "topmost" layer but only the one inside the MT spheres around the
> atoms that are defined to be in a selected layer.
> (Note, already for bulk materials, the total DOS is not the sum of the
> atomic DOSs)
> However, to what layer does the interstitial belong ? What if the
> surface is buckled ?
> And further, is the vacuum part of the "topmost" layer or not ?
> 
> I wonder whether the Critic 2 code of the Oviedo Group in Spain can
> help by using a Baader analysis,
> and to calculate the DOS inside of the space filling basins instead of 
> spheres.
> This might improve the situation but still leaves some questions open.
> 
> Ciao
> Gerhard
> 
> DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
> "I think the problem, to be quite honest with you,
> is that you have never actually known what the question is."
> 
> ====================================
> Dr. Gerhard H. Fecher
> Institut of Inorganic and Analytical Chemistry
> Johannes Gutenberg - University
> 55099 Mainz
> and
> Max Planck Institute for Chemical Physics of Solids
> 01187 Dresden
> ________________________________________
> Von: Wien [wien-bounces at zeus.theochem.tuwien.ac.at] im Auftrag von
> pieper [pieper at ifp.tuwien.ac.at]
> Gesendet: Donnerstag, 4. Mai 2017 10:22
> An: A Mailing list for WIEN2k users
> Betreff: Re: [Wien] DOS of slab
> 
> Assuming that you meant this to be a question, and that nobody answered
> up to now: If you want a plot of some partial DOS for a bulk crystal,
> you select an atom in the unit cell and possibly some orbital. Now you
> want to calculate the partial DOS of the topmost layer ... did you try
> (to understand) what happens if you select the atom(s) in your topmost
> layer?
> 
> 
> Am 29.04.2017 08:15, schrieb emami seyyed amir abbas:
>> Dear users.
>> 
>> I am trying to calculate the electronic and magnetic properties of a
>> thin film. I created a slab of 5 monolayer and run the scf. I desire
>> to obtain the DOS of the just  top monolayer but there is no option in
>> DOS program for this task. In DOS program i can plot DOS just for
>> specific atom not layer.
>> 
>> best regards.
>> _______________________________________________
>> Wien mailing list
>> Wien at zeus.theochem.tuwien.ac.at
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>> SEARCH the MAILING-LIST at:
>> http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
> ---
> Dr. Martin Pieper
> Karl-Franzens University
> Institute of Physics
> Universitätsplatz 5
> A-8010 Graz
> Austria
> Tel.: +43-(0)316-380-8564
> 
> 
> 
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---
Dr. Martin Pieper
Karl-Franzens University
Institute of Physics
Universitätsplatz 5
A-8010 Graz
Austria
Tel.: +43-(0)316-380-8564