[gpaw-users] gpaw-users Digest, Vol 175, Issue 6

[DAMEGARIN SAMBIANI]

Hi Mikael,

Thank you for the explanation. I understand that there isn't a direct 2D
Poisson solver with the logarithmic kernel in GPAW. The suggestion to
define a 3D density that is constant in the z-direction seems like a
practical approach.

However, I’m still a bit unclear on how to implement this. Could you
provide further details or an example on how to define this 3D density
correctly? I want to ensure I’m applying the approach accurately to achieve
the desired results on the xy-plane.

Thank you for your assistance!

Best regards,

SAMBIANI

PhD students

Le ven. 9 août 2024 à 14:25, DAMEGARIN SAMBIANI <sambianidamegarin at gmail.com>
a écrit :

> Re: Poisson GPAW
> Dear professor  Mikael,
>
> Thank you for your explanation. I am trying to implement this approach,
> but I am encountering difficulties. Could you provide me with a concrete
> example of code to help me better understand? And yes, I do want to
> consider the Coulomb interaction between two line charge elements.
>
> Thank you in advance for your help.
>
> Best regards,
>
> PhD student
>
> Le ven. 9 août 2024 à 14:07, Mikael Kuisma <kuisma at dtu.dk> a écrit :
>
>> Hi!
>>
>> >How can one physically explain adding a third direction that will be
>> constant?
>>
>> The constant direction will have a zero second derivative, thus the 3D
>> Laplacian operator will be effectively 2D. Physically, 2D poisson is
>> equivalent to solving 3D poisson with line charges defined by the
>> 2D-density (is this what you actually want, Coulomb interaction of two line
>> charge elements?).
>>
>> You can choose the Poisson solver depending on your required boundary
>> conditions, but the constant direction should be periodic.
>>
>> BR,
>> Mikael
>>
>> ------------------------------
>> *From:* DAMEGARIN SAMBIANI <sambianidamegarin at gmail.com>
>> *Sent:* Friday, August 9, 2024 3:53 PM
>> *To:* Mikael Kuisma <kuisma at dtu.dk>
>> *Cc:* gpaw-users at listserv.fysik.dtu.dk <gpaw-users at listserv.fysik.dtu.dk>
>> *Subject:* Re: [gpaw-users] gpaw-users Digest, Vol 175, Issue 6
>>
>> Dear professor Mikael,
>>
>> Thank you for your response. This means that I need to construct my
>> density in a 3D space. How can one physically explain adding a third
>> direction that will be constant? My density is constructed as follows:
>> ρ=ψ⋅ψ†. The values of ψ are obtained from the shifted matrix:
>> [E⋅S−H−self]⋅ψ=eigenvalue⋅eigenvector, from the self matrix. Additionally,
>> could you recommend a Poisson code that I could use.
>>
>> SAMBIANI
>> PhD student
>>
>> Le ven. 9 août 2024 à 11:45, Mikael Kuisma <kuisma at dtu.dk> a écrit :
>>
>> Hi!
>>
>> So effectively, you want to solve a 2D Poisson using a logarithmic kernel
>> ln |r-r'|, instead of the typical 1/|r-r'| kernel?
>>
>> There is no direct 2D poisson solver with that kernel in GPAW.  What you
>> could do, is to define a 3D density which is constant in z-direction,
>> AFAIK, up to possible prefactors, that should give the desired result on
>> xy-plane if one knows what one is doing.
>>
>> BR,
>> Mikael
>>
>> ------------------------------
>> *From:* gpaw-users <gpaw-users-bounces at listserv.fysik.dtu.dk> on behalf
>> of DAMEGARIN SAMBIANI via gpaw-users <gpaw-users at listserv.fysik.dtu.dk>
>> *Sent:* Friday, August 9, 2024 12:54 PM
>> *To:* gpaw-users at listserv.fysik.dtu.dk <gpaw-users at listserv.fysik.dtu.dk>
>> *Subject:* Re: [gpaw-users] gpaw-users Digest, Vol 175, Issue 6
>>
>>
>> Dear GPAW users,
>>
>> I have a concern regarding the use of GPAW's Poisson solver. I am
>> constructing my densities from wave functions that are in 2D, and I would
>> like to use this 2D density to solve the Poisson equation. However, the
>> Poisson solver code is designed in such a way that it cannot handle 2D
>> densities. I would like to know how to resolve this issue. Please help me.
>>
>> SAMBIANI
>>
>> PhD student
>>
>> Le ven. 9 août 2024 à 10:27, <gpaw-users-request at listserv.fysik.dtu.dk>
>> a écrit :
>>
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>> Today's Topics:
>>
>>    1. Re: PAW for Ce (Jens J?rgen Mortensen)
>>
>>
>> ----------------------------------------------------------------------
>>
>> Message: 1
>> Date: Thu, 8 Aug 2024 16:19:03 +0200
>> From: Jens J?rgen Mortensen <jjmo at dtu.dk>
>> To: Desalegn Nigatu <desalegnnigatu at gmail.com>,
>>         gpaw-users at listserv.fysik.dtu.dk
>> Cc: Thomas Bligaard <tbli at dtu.dk>
>> Subject: Re: [gpaw-users] PAW for Ce
>> Message-ID: <49258d40-ad70-4ff5-92c1-da9031a4df17 at dtu.dk>
>> Content-Type: text/plain; charset=UTF-8; format=flowed
>>
>> On 8/4/24 20:47, Desalegn Nigatu via gpaw-users wrote:
>> > Dear all
>> >
>> > Where can i find PAW for Ce?
>>
>> You can create a PAW-potential for Ce with this command:
>>
>>    $ gpaw dataset Ce -fPBE -s -r 2.5,2.4,2.4,2.2 -w
>>
>> Jens J?rgen
>>
>> > with regards
>> > _______________________________________________
>> > gpaw-users mailing list
>> > gpaw-users at listserv.fysik.dtu.dk
>> > https://listserv.fysik.dtu.dk/mailman/listinfo/gpaw-users
>>
>>
>>
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>> End of gpaw-users Digest, Vol 175, Issue 6
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