As far as I can see from a short browse, these methods are not "ab initio".
How would you calculate an "absolute electronegativity" from a DFT
calculation ???
I don't even know what this combined phrase means.
PS: A surface slab calculation shouldn't be too expensive ....
Am 20.12.2019 um 17:58 schrieb Subhasis Panda:
---
Dear Experts,
I wanted to calculate the absolute band edge energies for RbPbI_3
compound only (not any interface like RbPbI3 and TiO2 interface) in the
orthorhombic phase. As already suggested, it's a computationally costly
work and we don't have enough computational facility also in our
institute. I was searching in the internet and got the following
information. Looking forward to your expert opinion.
In the following reference, using Eqn 1(a) & (b) can we estimate that?
It requires absolute electronegativity of the semiconductor and the band
gap.
https://doi.org/10.2138/am-2000-0416
whereas in the following reference, the expressions are a little different.
http://www.rsc.org/suppdata/cp/c4/c4cp03494e/c4cp03494e1.pdf
Are these two expressions referring to the same thing? If not which one
shall we use. I've one more query, does absolute electronegativity of a
material (semiconductor) changes with its crystal structure type (like
bcc, fcc)?
Looking forward to your reply.
Thank you and best regards
Subhasis
On Fri, Dec 6, 2019 at 12:57 AM Peter Blaha
<pbl...@theochem.tuwien.ac.at <mailto:pbl...@theochem.tuwien.ac.at>> wrote:
This is not such a simple task. You will have to create a supercell
simulating the interface between the two materials.
The answer can change depending how you form the interface. Furthermore
this can be a complicated task, as the periodicity must fit and one has
to test/define various surfaces/interfaces (except if 2 materials
happen
to grow nicely epitaxically).
A simpler but much less accurate approach is to do 2 independent
surface
slab calculations with sufficient vacuum. From the difference of EF and
the coulomb potential in the middle of the vacuum (:VZERO) you get an
absolute band edge (actually this is the work function in a solid).
However, this method neglects band bending, charge transfer or dipole
formations at the interface, which could completely spoil the answer.
Am 05.12.2019 um 11:27 schrieb Subhasis Panda:
>
>
> ---------- Forwarded message ---------
> From: *Subhasis Panda* <onnyorup....@gmail.com
<mailto:onnyorup....@gmail.com>
> <mailto:onnyorup....@gmail.com <mailto:onnyorup....@gmail.com>>>
> Date: Wed, Dec 4, 2019 at 2:31 PM
> Subject: Band Edge position
> To: A Mailing list for WIEN2k users
<wien@zeus.theochem.tuwien.ac.at
<mailto:wien@zeus.theochem.tuwien.ac.at>
> <mailto:wien@zeus.theochem.tuwien.ac.at
<mailto:wien@zeus.theochem.tuwien.ac.at>>>
>
>
>
> Dear experts,
> How can I estimate the absolute band edge position (CB/VB) of a
> semiconductor using Wien2k?
> The attached figure is what I'm trying to get.
> Looking forward to your kind help.
>
> --
>
>
>
> Best regards,
> ------------------------------------------------------------
> Subhasis Panda
> Assistant Professor
> Department of Physics
> National Institute of Technology Silchar
> Assam, India - 788010.
>
> -------------------------------------------------------------
>
>
> --
>
>
>
> Best regards,
> ------------------------------------------------------------
> Subhasis Panda
> Assistant Professor
> Department of Physics
> National Institute of Technology Silchar
> Assam, India - 788010.
>
> -------------------------------------------------------------
>
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--
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-165300 FAX: +43-1-58801-165982
Email: bl...@theochem.tuwien.ac.at
<mailto:bl...@theochem.tuwien.ac.at> WIEN2k: http://www.wien2k.at
WWW:
http://www.imc.tuwien.ac.at/tc_blaha-------------------------------------------------------------------------
--
Best regards,
------------------------------------------------------------
Subhasis Panda
Assistant Professor
Department of Physics
National Institute of Technology Silchar
Assam, India - 788010.
-------------------------------------------------------------
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--
--------------------------------------------------------------------------
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Phone: +43-1-58801-165300 FAX: +43-1-58801-165982
Email: bl...@theochem.tuwien.ac.at WIEN2k: http://www.wien2k.at
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