[Wien] Regarding change of stoichiometry formula

[delamora]

Hitchhikers Guide to the Galaxy:

Page 24, third paragraph;

On Christmas day you should contradict anyone!

________________________________
De: Wien <wien-bounces at zeus.theochem.tuwien.ac.at> en nombre de delamora <delamora at unam.mx>
Enviado: domingo, 25 de diciembre de 2016 12:47:44 p. m.
Para: A Mailing list for WIEN2k users
Asunto: Re: [Wien] Regarding change of stoichiometry formula



8/3=2.4 ?????
*****Sorry, it is early in the morning (12:10 pm) Christmas day***********
In general, just to remove one atom in such a small supercell will give not realy good results
As it would lead to artificial symmetry, therfore, use better larger supercells and  remove several atoms
from different sites and finally average over various different configurations
------Although a large supercell is expensive
Maybe ATAT helps.

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 delamora [delamora at unam.mx]
Gesendet: Sonntag, 25. Dezember 2016 19:09
An: wien at zeus.theochem.tuwien.ac.at
Betreff: Re: [Wien] Regarding change of stoichiometry formula

No, this is not correct; if you want to make NbSe2.4 then you make a supercell that has 3 formula units, that would be Nb3Se9, then you remove one Se to have Nb3Se8=NbSe2.4

>From the above, you can see that to make NbSe2.6 is not as easy as NbSe2.4

But if you change the number of electrons then you are not removing atoms

If you want to make an "intermediate" element, for example, something between Mg and Al in MgB2 then you can add electrons to Mg in the struct file and in the *.in2 file, then you would have (Mg,Al)B2, this is the "virtual crystal approximation"

This virtual crystal approximation has been used to explain the experimental results for the Al and C doping of MgB2; (Mg,Al)B2 and Mg(B,C)2

________________________________
De: Wien <wien-bounces at zeus.theochem.tuwien.ac.at> en nombre de mandeep hooda <mandeep103 at gmail.com>
Enviado: domingo, 25 de diciembre de 2016 07:35:44 a. m.
Para: wien at zeus.theochem.tuwien.ac.at
Asunto: [Wien] Regarding change of stoichiometry formula

Dear Wien2k users,
                             I want to change NbSe3 to NbSe2.6 in Wien2k by creating supercell of NbSe3. I have read about how to add or remove electrons in .in2 file. How will I decide that this number of electrons should be removed so that I could get NbSe2.6.  Thanking you in advance



Regards
Mandeep Kumar Hooda
_______________________________________________
Wien mailing list
Wien at zeus.theochem.tuwien.ac.at
http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20161225/ddc50dcf/attachment.html>