[Pw_forum] adding vacuum

[Pascal Boulet]

Hello,

4 angstroms wide seems to be very small for the vacuum. As a rule of thumb you should use at least 2.5 times the thickness of your slab. This is what we observed in the calculations of semiconductor slabs. This has to be tested.

Pascal

Le 16 nov. 2015 à 16:40, Jaret Qi <jaretqi at yahoo.com> a écrit :

> Hello all,
> I am trying to minimize the interaction between my system and its periodic images. To do so, I introduced a layer of vacuum along the z-axis by increasing the lattice vector along the z-axis by 4A. At the same time, I fixed it by using this parameter: cell_dofree='2Dxy',
> But I have noticed atoms that are close to the vacuum move along the z-axis and vacuum is decreasing, is this wrong or I should use different cell_dofree?
> note:relaxation still ongoing, not relaxed yet.
> 
> 
> JARET,
> ASU
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--
Pascal Boulet - MCF HDR, Resp. L1 MPCI - DEPARTEMENT CHIMIE
Aix-Marseille Université - ST JEROME - Avenue Escadrille Normandie Niemen - 13013 Marseille
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