[Pw_forum] Image charge interaction

Tue Sep 13 17:34:02 CEST 2016

Or you can also use the simple dipole correction which was actually 
developed for charged (particles on) surfaces, see, e.g.,

Phys. Rev. B 59, 12301 (1999)

Phys. Rev. B 63, 205426 (2001)

On 09/13/2016 05:22 PM, Giuseppe Mattioli wrote:
> P.S.
> If your main concern is the vertical interaction between charges you
> can discard the interaction by using the ESM boundary conditions in a
> vacuum-slab-vacuum geometry (see the manual, the implementation is
> very simple and the calculation is stable in my hands).
> HTH
> Giuseppe
>
> Quoting Ilya Ryabinkin <igryabinkin at gmail.com>:
>
>> Hi Thomas:
>> SIC is definitely one of the ways to address this problem, but we also
>> thinking about tconstrained DFT approach. Unfortunately, this is more
>> i) long-term investment, ii) this doesn't rule out the problem of
>> image charge completely if a slab is too thin.
>>
>> BTW: it is written in a manual
>>
>>> This approach has known problems for dissociation mechanism driven
>>> by excess electrons.
>>
>> I wonder, what are these problems?
>>
>>
>> --
>> I.
>>
>> On Tue, Sep 13, 2016 at 10:01 AM, Thomas Brumme
>> <thomas.brumme at mpsd.mpg.de> wrote:
>>> 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
>>>
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>>
>>
>> --
>> *******************************************************
>>                      Ilya Ryabinkin
>>                   Postdoctoral Scholar
>>            Physical and Environmental Sciences
>>             University of Toronto Scarborough
>>    http://www.utsc.utoronto.ca/~aizmaylov/Members.html
>> *******************************************************
>>
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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