My first choice would be some self-interaction corrected functional - for this case special case something like this below (i.e. a perdew zunger SIC functional only on the excess charge) could be the simplest (it used to be implemented in CP):
https://journals.aps.org/prb/abstract/10.1103/PhysRevB.71.205210 A less poetic approach would be to use a hybrid functional (have a look at the bibliography for the Al substitution in SiO2) Plenty of literature on this general problem if you search. nicola On 19/02/2018 09:23, Christoph Wolf wrote: > Dear all, > > I have recently looked into color centers in ionic solids and I was > wondering if someone is familiar with a "reliable approach" to get the > charge states right? By that I mean the localization of a charge in > let's say Cl defective NaCl should have acquired an excess charge but > judging from postprocessing the cavity is only occupied by a fractional > charge and charges are spread around. > > I looked at the usual suspects in the examples and the mailing list but > it doesn't seem to have come up recently! > > Any hint is very appreciated! Have a great Monday! > > Best, > Chris > > -- > Postdoctoral Researcher > Center for Quantum Nanoscience, Institute for Basic Science > Ewha Womans University, Seoul, South Korea > > > _______________________________________________ > Pw_forum mailing list > [email protected] > http://pwscf.org/mailman/listinfo/pw_forum > -- ---------------------------------------------------------------------- Prof Nicola Marzari, Chair of Theory and Simulation of Materials, EPFL Director, National Centre for Competence in Research NCCR MARVEL, EPFL http://theossrv1.epfl.ch/Main/Contact http://nccr-marvel.ch/en/project _______________________________________________ Pw_forum mailing list [email protected] http://pwscf.org/mailman/listinfo/pw_forum
