[QE-users] PbTiO3 slab in vacuum with assume_isolated='2D'

[Pietro Davide Delugas]

Hi Lucian
The picture is visible, at least to me.

Pietro
________________________________
From: users <users-bounces at lists.quantum-espresso.org> on behalf of Lucian D. Filip <lucian.filip at infim.ro>
Sent: Monday, June 24, 2024 17:05
To: users at lists.quantum-espresso.org <users at lists.quantum-espresso.org>
Subject: Re: [QE-users] PbTiO3 slab in vacuum with assume_isolated='2D'


I am not sure if the picture I sent will be seen by someone since it doesn't appear here. I don't know what is the practice on this mailing list to show pictures.

On 24-Jun-24 1:24 PM, Lucian D. Filip wrote:

Sorry, for some reason the image was not attached to the message.

On 24-Jun-24 1:09 PM, Lucian D. Filip wrote:

Hello,

I am looking at a PbTiO3 slab in vacuum. The slab is in a polarized state and I am trying to obtain the Hartree potential with the dipole correction applied. I have seen that the assumed_isolated = '2D' option should do just that. However, I do not understand the result I am getting. In the attached picture I have plotted the Hartree potential averaged along the z axis, for the polarized state and the centro-simmetric state with polarization zero.

The slab is 5 PTO unit cells thick and there are 20 Angstroms of vacuum on each side. The vacuum region is well above the requirements of assume_isolated ='2D'. Can anyone explain two things:

1) why are there two regions in vacuum looking like a staircase.

2) why is there an electric field still present?


The weird artefacts at the edges of the supercell are due to the averaging procedure (i am still working on it, not sure where it is coming from).


Best regards,

Lucian


[cid:part1.xJhf4nbz.Uz4vUAqd at infim.ro]

--
Dr. Lucian Dragos Filip
National Institute of Materials Physics
Atomistilor str. 405A, PO Box MG. 7
Magurele, 077125
Bucharest, Romania
E-mail: lucian.filip at infim.ro<mailto:lucian.filip at infim.ro>
Website: https://lucianfilip.wordpress.com/

--
Dr. Lucian Dragos Filip
National Institute of Materials Physics
Atomistilor str. 405A, PO Box MG. 7
Magurele, 077125
Bucharest, Romania
E-mail: lucian.filip at infim.ro<mailto:lucian.filip at infim.ro>
Website: https://lucianfilip.wordpress.com/

--
Dr. Lucian Dragos Filip
National Institute of Materials Physics
Atomistilor str. 405A, PO Box MG. 7
Magurele, 077125
Bucharest, Romania
E-mail: lucian.filip at infim.ro<mailto:lucian.filip at infim.ro>
Website: https://lucianfilip.wordpress.com/
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