Re: [Pw_forum] Net Surface dipole

2016-01-28 Thread Giuseppe Mattioli

Dear Elliot and Uli
If you use the new esm implementation like this:

 &system
assume_isolated = 'esm',
esm_bc='pbc',
 /

pw.x automaticlly calculates the potential and charge density averages along z 
at the end of every scf convergence step and writes them on a 
prefix.esm1 file. If you set

 &system
assume_isolated = 'esm',
esm_bc='bc1',
 /

you decouple the pbc along the z direction in a vacuum-slab-vacuum 
configuration and you can obtain, e.g., two different vacuum levels on the two 
sides 
of the slab.

HTH

Giuseppe

On Wednesday, January 27, 2016 03:08:40 PM ulrich.ascha...@dcb.unibe.ch wrote:
> Dear Elliot,
> 
> If I understand your question correctly, then plot_num=11 (electrostatic 
> potential) with pp.x should give you that information. If you do a 1D plot
> along the surface normal and the potential does not become flat in the vacuum 
> region, then there is a net dipole.
 
> Best regards,
> -uli
> --
> SNF Prof. Dr. Ulrich Aschauer
> Universität Bern
> Departement für Chemie und Biochemie
> Freiestrasse 3
> CH-3012 Bern
> Tel. +41 (0)31 631 5629
> ulrich.ascha...@dcb.unibe.ch
> www.dcb.unibe.ch
> Büro: N431
> --
> 
> 
> On 27 Jan 2016, at 15:39, Elliot Menkah 
> mailto:elliotsmen...@yahoo.com>> wrote:
> 
> Dear All,
> How does one know or can one tell from the content of the output file of
> a full geometry optimization calculation (relax) that there's a net
> surface dipole density in an asymmetric system for adsorption studies.
> For eg. CO adsorbed on only one side of a nickel slab.
> 
> Thank you.
> 
> Kind Regards,
> Elliot.
> 
> --
> Elliot S. Menkah, AMRSC
> Research Student - Computational Chemistry/ Computational Material Science
> Theoretical and Computational Chemistry Lab.
> Dept. of Chemistry
> Kwame Nkrumah University of Sci. and Tech.
> Kumasi
> Ghana
> 
> Tel: +233 243-055-717
> 
> Alt Email: esmen...@knust.edu.gh
>   elliotsmen...@gmail.com
>   elliotsmen...@hotmail.com
> 
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Re: [Pw_forum] Net Surface dipole

2016-01-27 Thread ulrich.aschauer
Dear Elliot,

If I understand your question correctly, then plot_num=11 (electrostatic 
potential) with pp.x should give you that information. If you do a 1D plot 
along the surface normal and the potential does not become flat in the vacuum 
region, then there is a net dipole.

Best regards,
-uli
--
SNF Prof. Dr. Ulrich Aschauer
Universität Bern
Departement für Chemie und Biochemie
Freiestrasse 3
CH-3012 Bern
Tel. +41 (0)31 631 5629
ulrich.ascha...@dcb.unibe.ch
www.dcb.unibe.ch
Büro: N431
--


On 27 Jan 2016, at 15:39, Elliot Menkah 
mailto:elliotsmen...@yahoo.com>> wrote:

Dear All,
How does one know or can one tell from the content of the output file of
a full geometry optimization calculation (relax) that there's a net
surface dipole density in an asymmetric system for adsorption studies.
For eg. CO adsorbed on only one side of a nickel slab.

Thank you.

Kind Regards,
Elliot.

--
Elliot S. Menkah, AMRSC
Research Student - Computational Chemistry/ Computational Material Science
Theoretical and Computational Chemistry Lab.
Dept. of Chemistry
Kwame Nkrumah University of Sci. and Tech.
Kumasi
Ghana

Tel: +233 243-055-717

Alt Email: esmen...@knust.edu.gh
  elliotsmen...@gmail.com
  elliotsmen...@hotmail.com

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[Pw_forum] Net Surface dipole

2016-01-27 Thread Elliot Menkah
Dear All,
How does one know or can one tell from the content of the output file of
a full geometry optimization calculation (relax) that there's a net
surface dipole density in an asymmetric system for adsorption studies.
For eg. CO adsorbed on only one side of a nickel slab.

Thank you.

Kind Regards,
Elliot.

-- 
Elliot S. Menkah, AMRSC
Research Student - Computational Chemistry/ Computational Material Science
Theoretical and Computational Chemistry Lab.
Dept. of Chemistry
Kwame Nkrumah University of Sci. and Tech.
Kumasi
Ghana

Tel: +233 243-055-717

Alt Email: esmen...@knust.edu.gh
   elliotsmen...@gmail.com
   elliotsmen...@hotmail.com

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