Thanks everyone for the advices.
But I think I am facing a bigger problem. I would like to analyse the interface 
between a metal and a semiconductor, but many issues come to my mind:
1. how should I define the system? I will have a system requiring smearing 
while the other won't;
2.how to relate celldm() to the correct system?
3.still the building of "CELL_PARAMETERS" card is obsure to me for this kind of 
mixed system.
Thank anyone who wants to help.
Lorenzo.

Sent from my ASUS

-------- Messaggio originale --------
Da:Giuseppe Mattioli
Inviato:Wed, 21 Sep 2016 15:39:03 +0200
A:pw_forum@pwscf.org
Oggetto:Re: [Pw_forum] mixed supercells


And if you have no experimental hint of the behavior of cell parameters at the 
interface you can start by averaging the parameters, with a (hopefully
little) strain of both materials.

HTH

Giuseppe

On Wednesday, September 21, 2016 03:09:49 PM Jess Wellendorff wrote:
> The VNL "Interface Builder" would make it very easy for you to build a
> minimum-strain interface:
>
> http://docs.quantumwise.com/tutorials/ag_au_interface/ag_au_interface.html
>
> On 09/21/2016 03:04 PM, Lorenzo Paulatto wrote:
> > Dear Lorenzo,
> > you cannot specify different periodicity, you have to build a
> > super-cell, as big as the 3x3 cell of the first material, or the 2x2
> > cell of the second, then you fill it with 9 units of the first
> > material and 4 of the other. This can be done by hand (the first time
> > it'll take you an hour or two), or there are some softwares that can
> > help you I have never used one, as hence I cannot recommend any.
> >
> >
> > On 21 September 2016 at 14:46, Lorenzo Pedrazzetti
> > <lorenzo.pedrazze...@polimi.it <mailto:lorenzo.pedrazze...@polimi.it>>
> >
> > wrote:
> >     Good afternoon,
> >
> >     I am trying to model the interface between two solid with
> >     different cella parameter. By looking at their experimental cell
> >     value I am supposed to stack a 3x3 slab onto a 2x2 slab made of
> >     different material.
> >
> >     My problemi s the “CELL_PARAMETERS� card; i found some
> >     difficulties to understand how to specify the different
> >     periodicity of the two materials.
> >
> >     Thanks a lot,
> >
> >     Lorenzo.
> >
> >
> >     _______________________________________________
> >     Pw_forum mailing list
> >     Pw_forum@pwscf.org <mailto:Pw_forum@pwscf.org>
> >     http://pwscf.org/mailman/listinfo/pw_forum
> >     <http://pwscf.org/mailman/listinfo/pw_forum>
> >
> > _______________________________________________
> > Pw_forum mailing list
> > Pw_forum@pwscf.org
> > http://pwscf.org/mailman/listinfo/pw_forum

********************************************************
- Article premier - Les hommes naissent et demeurent
libres et égaux en droits. Les distinctions sociales
ne peuvent être fondées que sur l'utilité commune
- Article 2 - Le but de toute association politique
est la conservation des droits naturels et
imprescriptibles de l'homme. Ces droits sont la liberté,
la propriété, la sûreté et la résistance à l'oppression.
********************************************************

   Giuseppe Mattioli
   CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
   v. Salaria Km 29,300 - C.P. 10
   I 00015 - Monterotondo Stazione (RM), Italy
   Tel + 39 06 90672342 - Fax +39 06 90672316
   E-mail: <giuseppe.matti...@ism.cnr.it>
   http://www.ism.cnr.it/en/staff/giuseppe-mattioli/
   ResearcherID: F-6308-2012

_______________________________________________
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum
_______________________________________________
Pw_forum mailing list
Pw_forum@pwscf.org
http://pwscf.org/mailman/listinfo/pw_forum

Reply via email to