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 <igryabin...@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.bru...@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.paula...@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 >>>> >>>> _______________________________________________ >>>> Pw_forum mailing list >>>> Pw_forum@pwscf.org >>>> http://pwscf.org/mailman/listinfo/pw_forum >>> >>> >> >> -- >> 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.bru...@mpsd.mpg.de >> >> _______________________________________________ >> Pw_forum mailing list >> Pw_forum@pwscf.org >> http://pwscf.org/mailman/listinfo/pw_forum > > > > -- > ******************************************************* > Ilya Ryabinkin > Postdoctoral Scholar > Physical and Environmental Sciences > University of Toronto Scarborough > http://www.utsc.utoronto.ca/~aizmaylov/Members.html > ******************************************************* > > _______________________________________________ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum -- ******************************************************** - Article premier - Les hommes naissent et demeurent libres et égaux en droits. 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