[Pw_forum] Image charge interaction

[Thomas Brumme]

Hi Ilya,

I wonder if the SIC implementation in CP can help:

http://www.quantum-espresso.org/wp-content/uploads/Doc/cp_user_guide/node11.html

Unfortunately, I'm not familiar with CP...

Regards

Thomas


On 09/13/2016 03:44 PM, Ilya Ryabinkin wrote:
> 2NIcola:
>
>> If I understand this correctly, it seems a less satisfactory answer that
> just having the uniform jellium background?
>
> No. In particular, I have Cl- species in my system, but there is no
> way in common GGAs to keep an electron on chlorine -- due to self
> interaction the electron is too weakly bound (if any) to Cl and DFT
> gives a completely wrong, de-localized solution for an extra electron.
> Neutralizing background will simply eat up the field of this
> delocalized electron and I'll be simulating a system which resembles
> more a *neutral* Cl atom on a slab rather than an anion.
> One of the possible ways to work around -- is to devise a
> pseudopotential for Cl with the configuration [He] 2s^2 2p^5 3s^2
> 3p^6, which has a hole in 2p and an extra electron in 3p, then "bury"
> the hole inside a pseudopotential... This solution, however, leads to
> the apparent lack of charge-image interaction since the resulting
> pseudoatom is neutral (in fact, it looks like Ar).
>
>> the state of charge of your particle
>> will be determined by the physics - i.e. the xc functional will decide
>> how much charge should sit on the particle
> I wish it could be true... but not for the common DFA-s
>
>> Which capability? Adding an empirical extra term in the forces for
>> the charge?
> Yes. I'm wondering if some one already did this. I can do it myself,
> but for the sake of not re-inventing the wheel...
>
> I.
>
> On Tue, Sep 13, 2016 at 6:26 AM, Lorenzo Paulatto
> <lorenzo.paulatto at impmc.upmc.fr> wrote:
>> Hello,
>> it is not too clear to me what you need, but is something like this: http://
>> journals.aps.org/prb/abstract/10.1103/PhysRevB.89.245406 ?
>>
>> It is implemented in the upcoming version 6.0 of QE,
>> The feature is still disabled in the downloadable beta versione, but it is
>> enabled in the last daily snapshots at http://qe-forge.org/snapshots/ (no
>> guarantee anything works).
>>
>> hth
>>
>> On Monday, 12 September 2016 18:13:25 CEST Ilya Ryabinkin wrote:
>>> Dear colleagues:
>>> I am simulating dynamics of a charged particle on a metallic slab. To
>>> avoid difficulties with Coulomb energy of a charged cell, we use a
>>> core-hole trick to introduce a compensatory positive charge directly
>>> into a particle. However, the image-charge interaction is clearly
>>> absent and we would like to bring it back.
>>>
>>> Did anyone bother him/herslef to implement is in QE? I know VASP has
>>> this capability, but it is out of scope.
>>>
>>> Thanks in advance,
>>> I.
>>
>> --
>> Dr. Lorenzo Paulatto
>> IdR @ IMPMC -- CNRS & Université Paris 6
>> +33 (0)1 44 275 084 / skype: paulatz
>> http://www.impmc.upmc.fr/~paulatto/
>> 23-24/4é16 Boîte courrier 115,
>> 4 place Jussieu 75252 Paris Cédex 05
>>
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>

-- 
Dr. rer. nat. Thomas Brumme
Max Planck Institute for the Structure and Dynamics of Matter
Luruper Chaussee 149
22761 Hamburg

Tel:  +49 (0)40 8998 6557

email: Thomas.Brumme at mpsd.mpg.de