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 <[email protected]> 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 >> <[email protected]> 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 >>> [email protected] >>> 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: [email protected] > > _______________________________________________ > Pw_forum mailing list > [email protected] > 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 [email protected] http://pwscf.org/mailman/listinfo/pw_forum
