[Pw_forum] Excited Atom Approaching a Surface

[Nicola Marzari]

Dear Vic,


in the weak coupling regime one could use constraints (Wu and Van
Voorhis, PRA 2005) or penalties (Sit, Cococcioni, Marzari, PRL 2006);
see e.g. this paper for an application to metal/molecule interfaces:
http://prb.aps.org/pdf/PRB/v88/i16/e165112

None of this is currently implemented in QE, although the penalty
work is a fairly straightforward extension of DFT+U - but it would
still require some coding.

				nicola



On 01/02/2014 19:14, Vic Bermudez wrote:
> Hello,
>
> 	I would like to compute the total energy vs. distance for an argon atom, in
> the lowest-energy excited state, approaching a metal surface. The most
> straight-forward way to do this, it seems, would be to use
> Occupations='From_Input' and then use the Occupations card to specify the
> [Ne]_(3s)2_(3p)5_(4s)1 configuration for the argon. However, if I do that
> then I can't also specify Occupations='Smearing', which I need for a
> metallic substrate. Or can I ? Can the Occupations keyword be used twice,
> and if I could do this then how would I choose 'nbnd', which has to be
> specified for Occupations='From_Input' ? Is there a reasonable way to
> approach this kind of calculation in Quantum Espresso ? I've searched the
> User Forum but couldn't find anything helpful on this subject.
>
> Thanks,
> Vic Bermudez
>
> Victor M. Bermudez
> Code 6876
> U.S. Naval Research Laboratory
> 4555 Overlook Ave., S.W.
> Washington, DC 20375-5347
>
> Phone: 202-767-6728
> FAX: 202-767-1165
> E-mail: victor.bermudez at nrl.navy.mil
>
> _______________________________________________
> Pw_forum mailing list
> Pw_forum at pwscf.org
> http://pwscf.org/mailman/listinfo/pw_forum
>


-- 

----------------------------------------------------------------------
Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL